Legal Question in Civil Litigation in Pennsylvania

Her rights are none concerning ownership of the car unless she is on the title (in which case she would be a co-owner, not just a co-signer).

Why would the police be involved? Your daughter, if she is just a co-signer, has no right to take the vehicle. She has a "right" (more like a responsibility) to pay for it if the boyfriend does not make the payments (which he probably will not) and your daughter wants o protect her credit. If neither your daughter nor the boyfriend pays, the lender will come and repo the car. However, the repo will be on your daughter's credit and the lender may try to come after her for any deficiency balance owed.

Co-signing is a BAD BAD BAD idea for anyone. When a person agrees to co-sign, the co-signer is in effect saying to the bank "go ahead and lend the other person money because if he does not pay the bill I will." And the person who needs a co-signer means either that the person has no credit or much more likely, a history of bad credit. If the latter, then it means that your daughter is just the latest victim by a deadbeat who preys on women to buy him things and then leaves them stuck with the bills.

If, by some chance, your daughter is a co-owner, that means that she has an equal right to possess the car. However, the police are not going to want to get involved if both your daughter and the boyfriend are both on the title. In such case, its a civil remedy and they can seek partition of the car. Or your daughter can try to buy the boyfriend out. If she wants the car, perhaps that may be the best option.