rodburner, what indicated that the car is actually two cars? are half the vin's different?, if so, how did it have a clean car fax?, did you buy from a dealer?
oopps, seems like I am the one asking all the questions, sorry. One more, what kind of problems are you having. If it is backhalved, I think I would contact the entity that sold it to you, and complain to the DMV.

Dean