Automatic Transmission problems of the 2005 Mini Cooper Convertible

Hi, I'm writing to report that my 2005 Mini cooper, with less than 43k miles is in need of a third transmission. I nearly did not make it home one evening because the jerking motion the car was making and because the engine just felt like it was going to shut off. I nearly stalled on the highway, while in traffic. The first transmission, while under warranty was replaced in November 2007 at 28k miles. On 12/16/08, I had an accident where the transmission pan among other things had to be replaced. It was the only known damage caused to the transmission. The auto body and paint shop that I contracted with did not know how to fill the transmission fluid and therefore the car had to be towed the local Mini cooper dealership. They performed that piece of it. Now, the dealer is telling me I need a new transmission and the car is out of warranty. The dealership also states they don't know if the transmission damage was a residual of the accident or not and therefore, were trying to open up the old insurance claim from January 2009. However, my insurance company does not want to pay for the new transmission because they state the repairs from the accident $7,888. 70, plus the cost of a new transmission, around 8k will be more than the value of the car. So, who should pay for this new transmission, the dealer, the auto body shop (whom did no work on the transmission, seemingly) or me? how do I know, this is not just another bad transmission? there is no way to tell on a Mini cooper (no way to check) transmission fluid and no indicator light came on.