<human>: Can you summarize the given text in a few sentences?

So 4 years ago my brother in law got in an accident with his 2005 Saturn Vue.  Well insurance fixed the car all up but he never felt safe driving it again.  He bought a new car without trading it in leaving them with an extra car and a grumpy wife.  We were looking to get another car anyways and the car was suitable and met our basic requirements.  My Brother in law still needed to have the car in his name because he was still paying on it and we agreed that I'd pay the majority of the payment and he'd make up the rest for the obvious depreciation of the car.  Fast forward 3 years and the transmission fails, which normally I would consider my problem, however the transmission has a class action lawsuit settlement because it's known to be faulty and fail early.   He either was never notified of the lawsuit, or doesn't remember it but now GM is offering $5,000 toward the purchase of a new car in compensation but the catch is it has to be in his name.  He can't secure financing for another car.  The value of the car still runnning is ~$7,800 with no tranny though it's worth about nothing.  The car has been sitting idle for 6 months while I try to figure something out to put together the $3,400+ to rebuild the transmission.  I want to be fair about it but if I were the owner of the car I would be suing somebody or getting a chunk of change towards a new car neither of which I can do.  After making the payments for the last 6 months pestering them to work something out I told him that I'm not making any more payments until we work out a deal.  I would love a neutral opinion.
<bot>: Took over payments from my brother in law for a car with a faulty transmission, because I'm not the owner I don't qualify for the settlement.  Should I still be responsible for the whole cost of repair?