Legal Question in Civil Litigation in Nevada

I assume you just made the payments on the loan that had his name still attached. If the title remains in his name, then you really did not get anything out of the deal but the use of the vehicle for two years. Now, if he demands his car, you really don't have much of a legal leg to stand on, since the title says it is his and the loan is all paid up and current. I'll assume you did not enter any sort of contract with him, clearly expressing what was to happen when you took over his payments. The reality is that now you will have to give him back his car and consider the payments you made in his behalf to be, essentially, rent for its use for those two years. Without any written contract to the contrary, you'll have a very hard time demonstrating you are entitled to any more than the use of the car for the two years that you paid for.