What can I do with this car?

On 28 january 2007 , my wife and I bought a 1999 Jeep Grand Cherokee Limited V8 at a buy here pay here dealership in Atlanta . Because of our bad credit , the 14% interest rate he offered and plan to paye off the car in under two years for the $11,500 amount seemed good. we put down $2000 and made payemnts of $400/mth.well, two weeks form the date of purchase the radiatopr started leaking and overheated the engine. the edealer was out of the country so the car was not attended to for alomsot tow months and we finally got it bak in May. We still made our payments despite this and the dealer told us the we had to share the cost on replacing the engine since the car was sold AS IS.this cost us $2500. well, tow weeks ago , the radiator started leaking and we called the edaler to avoid the lsat sistuation. he sent his mecahnic who drove the car. well , ten miles on the way to the dealer , teh engine shut down . it was overheated again and thsi time he said that he would cover all costs.