PLEASE HELP!!!

My car has now been in the shop for 31 days. I call and speak to the general manager every day. Quick background, they had it for two weeks, got a new part in and I got the car back and had it for FOUR days before it broke again and they had to tow the thing to the dealership. The dealership is giving me the run around, telling me they keep calling Chrysler and the part from Germany isn't able to be tracked and that it maybe this week or next (heard this about a month ago). I'm paying almost $600 bucks a month for a crossfire and I'm driving a honda accord, that I can't drive more than 50 miles a day on (per Enterprise)!!! I looked up texas lemon laws but I hear that only applies to new vehicles. I purchased mine used and it still has the Chrysler warranty... What should I do??? I'm getting royally screwed here.