Legal Question in Civil Litigation in Pennsylvania

Re: civil law

You cannot undo a gift. Once gifted, the item is the property of the recipient.

The question is if it is provable as a gift, or if there's evidence that it was actually part of some deal between you two. Since title is in your name, the burden would be on her to demonstrate that you made some agreement in consideration for receiving the car.

As another matter: I hope you've consulted your tax professional regarding the consequences of that large gift. If not, now may be the time to consult them.