I think it is possible, but you will have a difficult time, at best, to either get refunded the money you spent, or to claim "ownership" of your car, because the title is not under your name. Generally speaking, ownership is proven by the title that is registered with your state's Department of Motor Vehicles. However, if you have a written agreement with your boyfriend, or even a letter, a note, or any kind of written document in which he states that you will own the car if you make all of the payments, then you would have a good legal argument to make, based on the following reasoning: A contract is formed when two people come to agreement that if one person does one thing, than the other will do the other thing. In your case, you seem to have a VERBAL agreement with your boyfriend, that if you make all of the payments on the car, (which you have), then title of the car should be transferred to you. However, even assuming that a verbal agreement would be considered sufficient in your state, you do need to have some kind of proof of that agreement -- perhaps the testimony of someone who is aware of the agreement, like a friend or relative. It would be much stronger evidence, if you had, as I mentioned above, something in writing that is signed by your boyfriend, because that would be more readily accepted by a court that he intended to be legally bound by his word that the car would be yours if you made all the payments (or at the very least, that the monies you paid would be returned to you). There is also another way you could approach the problem with a court, and that is, under the rules of "equity" or "fairness." There is an equitable doctrine of law that if someone does something that they didn't have to do, with the understanding that there would be a certain result if they did so, and if that first person did that thing "to their detriment," then they should get the expected result. So, in your case it would work this way: even if you didn't have an actual "agreement" with your boyfriend, if instead, you relied on his "promise" to give you the car as long as you paid for it, and you did make all the payments (which is what is meant by doing something "to your detriment," because you have spent money on the car), then a court should order that either you be refunded the money that you paid, or that title to the car be transferred to you -- because of this equitable principal.
