Warning: If you got upset by the first file, it may not be such a good idea 
to keep reading this one. If you're looking for a happy ending (i.e. someone finds out about Leona's predicament, and they either find a loophole after all or they just kidnap her and "deprogram" Dotty - or perhaps her popularity starts dwindling until the studio lets her go on their own) you won't find it here. Well, not below anyway - looks like I just came up with a few to explain what you won't find here!

Uhm, I came up with some more ideas while taking a short break from typing this. Not really a complete happy ending, but a few random ideas, so I'll do them first.
Somehow Leona's friends/aquaintances start figuring out the truth behind Dotty the Polkadot Lion (possibly Yin starts getting ideas first, and the others realize she's less crazy than usual), and Tiffany get sufficiently convinced to ask Drezzer (who's got contacts in the business) to arrange for the two of them (Tiff and Dot) to meet under four eyes.
At this close range Tiffany has no problems verifying that Dotty both smells and feels like Leona, and except for that silly polkadot pattern she looks like her as well. (It may be an idea to make Tiff repeat the recognition sequence Leona did while watching the first show: Her face, her figure etc.) She just doesn't act or sound like her (her voice does, but not the way she speaks or what she says), and does not seem to remember her old name or her rival.
As Dotty polkas away at the end of the meeting, Tiffany remains standing around with a shocked expression until Drezzer comes over to pick her up (You know what I mean...).
"What's the matter, Tiff? You look like someone just walked across your grave."
"Someone did."
"Come again?"
"I just saw Leona walk across her own grave. And she was dancing!"

Well, so much for that. Speaking of grave, that's what the rest of this is. Here's the original beginning of this file:

------------

There's another Pink Floyd quote that would seem appropriate here:

"Did you exchange
 a walk-on part in the war
 for a lead role in  cage?"

That is Leona's new life - a lead role in a cage. Of course she wants out, but there is no legal way to do it.
No _legal_ way. But there is one way out of everything that all the world's lawyers can't block for anyone. There are two sure things in life, and this time it's not about taxes...
One dark night Leona sneaks past her guards (see below), gets into the Ferrari Dotty bought her, and drives off into a short future.
Reaching the freeway - a term that has a new meaning for her that night - Leona cruises until she finds a suitable place for her last exit, then she floors the accelerator, closes her eyes and lets go of the wheel. Her last conscious though is "Make it quick...!"

In a way, her last wish is granted. It is Dotty who wakes up in a hospital bed several hours later. Once she has finished laughing at the bandages and casts that make her look like a snowman (!), they explain to her what seems to have happened.
When her head hit the windshield, it ruptured a blood vessel in her brain, necessitating immediate surgery to stop the bleeding and patch her up. (Okay, so I'm no expert - as far as I know such an injury might be immediately fatal.) But something else happened on the table as well.
Apparently her two personalities had become so different that they started occupying separate parts of the brain, and in his haste to save her life, the surgeon accidentally isolated and deactivated Leona's part.
To put it simply: Leona is gone, leaving Dotty as the sole heir to her body. The good news is that they won't have to hypnotize her any more - from now on she's Dotty 24/7.

But wait, there's more! In the next scene the executive we've met earlier is discussing the latest turn of events with his assistant, when the asistant points out how convenient it was that Leona got lost and Dotty saved. After all, Dotty is well on her way to stardom (and the sympathy she  gets after the "accident" (the one on the freeway, not the one on the operating table - only a select few know about that one) is going to boost her popularity even further), but Leona was just going nowhere fast.
After a moment's hesitation the executive admits that it was not entirely an accident. Or even not at all. The board has been concerned about the possibility of Leona messing up things for quite some time, and when this surgery came up, he seized the opportunity and put the company's bribe account to good use. By paying the surgeon to eliminate Leona, he became the first person in history to get away with murder because the victim is still alive...!
[Okay, that was pretty farfetched - it would require someone to find out about the personalities splitting up before Leona got wiped out, right?]

And still there's more. Weeks pass, Dotty gets out of hospital and returns to work just as the studio is about to run out of episodes produced before the "accident". When she returns for a checkup, the doctor scans her brain and looks surprised at the results, but quickly assures Dotty and her companion that everything's alright. He just needs to do one more test.
Holding an electrode to the side of her head and keeping an eye on the instrument it's attached to, he mutters a couple of unintelligible words, blinks twice at the reading and turns off the instrument. Dotty wonders what he said, but he replies "Just some technobabble" and dismisses the patient without explaining the last test.
Later the doctor finds that he can't tell anyone what he just discovered, but he can't just keep quiet, so he explains it to his goldfish. (A pretty thin plot device to explain it to the reader...)
What he found out during the brain scan was that there is still some activity in the isolated part of Dotty's brain, and it seems to be influenced by whatever she sees and hears. To paraphrase Pink Floyd again, there's someone in her head and it's not her. As this is a simplified version of reality, there can only be one explanation: Leona isn't gone after all. Her mind is still there in the sequestered part of the brain, and she can see, hear and feel, but not react in any way (not any way detectable by normal senses at least). All the botched surgery has done, is to make her a mute paraplegic living in someone else's body.
The final test seems to verify the theory. What the doctor did was measure the activity in the isolated brain parts while he said "Leona, I feel your pain" in swahili. The reactions indicated that even though Dotty didn't understand the words, something did.
Explanation time again. Dotty was created as a tabula rasa, and only ever learned the things she needed to know to play her role. Unlike Leona, she did not know how to drive a car, she just got the Ferrari because she thought it would look cool standing in the driveway. And while Leona was born and raised in Serengeti and speaks the language fluently (or could speak it while she still had access to her mouth), Dotty was created in the  studio and only knows English.
The story ends with a disturbing symbolic picture of Leona's trapped mind (verifying the doctor's theory - which will remain a theory to him - to the reader). I've got two ideas for that. (Both show her with her original fur, suggesting that this is not her physical body but her soul.)
In the first she's gagged and tied hand and foot but still able to see and hear. In the second there is nothing to tie or gag - no arms, no legs, and no mouth. She is pleading silently (lacking a voice to plead out loud):
"I'll be good!
"I'll do anything!
"Just give me my body back!"

The. End.

And if you still think you'll be able to sleep tonight, I've got a couple of details and alternative endings.
Writing that bit about sneaking past her guards I got the idea that the best way to do that would not be to avoid detection, but to hide in plain sight by trying to pass herself off as Dotty! The irony is that to escape the mess she got into because nobody thought she could play the role, she has to play the role!
Thinking about it some more, I came up with this scene:

Time: Well after sundown
Place: The garden of a stately bungalow. No sign of life except for two tired guards on the patio. As already suggested, there's a Ferrari parked in the driveway. (I'm making it a bit easier for Leona here, she would have a rough time trying to get to the car with the guards watching if it was locked up in the garage.)
The silence is abruptly shattered as a door flies open, and Leona comes dancing down the stairs, laughs at the guards and starts telling them how silly they look. (More irony: She's making the performance of her life in order to end it!)
The guards look puzzled, and after checking his watch one of them asks "Dotty" what she's doing here this late. Isn't she supposed to be Leona at this hour?
She answer yes, normally she isn't up this late, but there's a full moon ("Bet you didn't notice, huh?"), so she asked the hypno guy to give her a few more hours so she could stay up and howl at the moon!
After a brief discussion the guards let her pass, and as she does so, she glances in the direction of the driveway and makes a mental note that the car she's found the keys for is still in the drive. (This is supposed to be the reader's first hint that we are watching Leona and not Dotty.)
She does not go straight to the car, of course, but spends some time cavorting in the garden, howling at the moon and laughing at everything in typical Dotty style until the guards start relaxing. As she "happens" to wander across the driveway, she suddenly spins around and stares at the car, claiming that it's making faces at her! She makes some faces back, shouting at the car to "take that back" and silly stuff like that.
Suddenly she runs up to the car and somersaults over the hood into the driver's seat with a mental remark that these antics are killing her - not that that isn't the idea! After pausing to catch her breath, she leans over in the passenger seat to howl at the moon again - conveniently blocking the guards' view of the dashboard so they don't see her taking the keys out of her pocket and inserting the ignition key in the lock.
A small twist from freedom (however temporary) she straightens up and shouts: "Hey guys!"
"What?"
There is a brief pause that Leona uses to get her feet positioned on the right pedals.
"Oh come on (she names the guard who didn't speak), aren't you curious too? 
Let's try again...
"Hey guys!"
"What?"
"What?"
She stops grinning, flips them the bird and says in her most un-Dottylike voice: "You're fired!!"
While they are pondering that one, she starts the car and spins off, kicking up half the gravel in the drive in the process. As the tail lights recede into the distance, the penny drops.
"Dotty can't drive!"
"Yeah, there's a lot of things they won't let her do..."
"I mean she _can't_! She doesn't know how!"
"You mean...?"
"That's Leona!"
The chase is on, only to end in a brick wall twelve minutes later.

Okay, looks like there's gonna be some more happy endings after all. I came up with some variants of the above while typing it. The first twist is that  it's Leona who wakes up in the hospital, so it's a bit brighter already. One variant of this is that her fur is so badly singed and/or discoloured they can't make out the polkadots, so they have no idea she's a TV star. When she realizes this, Leona pretends to have lost her memory and gets booked as Joan Doe. Rather incredibly, the studio is unable to track her down, and so she is off the hook and free to start a new life elsewhere.

Well, that was not entirely happy because Leona is still lost to her friends. How about this: They have found her, but decide to let her remain herself until she's recovered. But she's still under contract, and so the day eventually comes when she has to become Dotty again - either when she returns to the studio, or when they decide to have a press conference at the hospital as soon as she's well enough. But somehow it doesn't work out that way. It turns out that Dotty has been "deactivated", and somehow Leona does not have enough "material" in her to build another fake personality. No matter how they try, she remains good (?) old Leona. So they finally give up and release her from the contract. Good ridddance! [It's possible that she does agree to play the role one more time for the press conference, on the condition that she gets to announce Dotty's retirement. Which wraps up the official version of the story pretty neatly in the eyes of the media at least. After all it's rather plausible that even someone like Dotty would lose her carefree outlook after a near brush with death.]

Another twist: She gets disfigured. Not much, not really hideously, but she is sufficiently different from her old look to not fit the description of the ideal Dotty any more. If they tried to put her back in the show now, it would flop.

Or it could simply be that the crash has changed Dotty in the eyes of her fans. She was a careless clown, now she is a heroine - and her old personality just won't work with that. So they have to drop her and come up  with something new. One possibility is that they try to rework Dotty's character to make her more like Leona (!), and so she gets to stay on the show playing a much easier role consciously without any special trickery.
Of course she does get the privilege of firing most of the staff that mistreated her.

Running out of space again, let's see if I can squeeze in the rest of the unhappy endings. They are rather similar to the first one actually.
In the first (which I actually thought of last) Leona realizes that Dotty is taking more and more of her time, and there is no way out, so she decides to throw in the towel while she's still got it. On her way to the studio the next day she makes a detour to the bank (under strict supervision of course), and when she meets her "therapist" again she offers him a bundle of cash to do one thing for her - or rather NOT do one thing. She doesn't want him to "wake" her up again at the end of the day. Let her remain Dotty, she'll be happier that way...

In the other variant she does not even take that initiative. Dotty keeps taking up more of Leona's time, there are even days when all she gets to do is get up in the morning and go to bed at night - Dotty spends the whole day not only working on the original show, but also dubbing foreign versions (noone else can do that wild voice), making public appearances - you name it. The board is concerned that Leona may start worrying about it, so even without discussing it with her, they decide to jump the gun and exercise the last option in her contract - to make Dotty a full time loonie...

Made it!