Welcome! My goal is to do my very best to understand your situation and to provide a full and complete answer for you.
Good afternoon. Your friend has as much right to the car as his nephew. If your friend gives the documentation you reference, plus a notarized limited power of attorney
authorizing you to act on his behalf to take the car, then you could not be prosecuted for taking the car. Under PA laws, you must not either breach the peace or break and enter to take the car. Once you have the car, your friend should file suit against the nephew for the nephew's share of the payments. That will give him the leverage and options he needs to get the nephew off the title. Once the suit is filed and a judgment awarded, he becomes a judgment creditor
, and he has the right to take the nephew's ownership interest in the car to collect that judgment. As long as your friend is on the title, he definitely does not want to drop his insurance coverage. Without insurance coverage he risks being sued and held personally liable for an accident caused by the nephew.
Thank you so much for allowing me to help you with your questions. I have done my best to provide information which will be helpful to you. If I have not fully addressed your questions or if you have any follow up questions, or if I have misinterpreted your questions in any way, please do not rate me yet, but simply ask a follow up question without rating so I can provide you with a fully satisfactory answer. If I have fully answered your question(s) to your satisfaction, I would appreciate you rating my service with 3, 4, or 5 faces/stars so I can receive credit for helping you today. I thank you in advance for taking the time to provide me a positive rating!