Can I be sued from a "buy here/pay here" car lot, if I a car be repossessed by the seller?

Question Details:

I bought a car 4 years ago; 2 years later the engine blew up for the second time. I had the car towed to the repair shop. I then called the seller and told him I was done with the car and that he could come get it or have it towed to his lot. I didn't hear anything. Then today, I got papers stating I'm being sued for not paying the car off. I haven't had the car in my posession for 2 years. Can I fight this? Important Notice