You will need to check with the Driver and Vehicles Department of PennDOT to find out how to legally handle a parts or project car that will not be driven.

A PennDOT fact sheet does note that insurance companies are required to notify PennDOT when an insurance policy is cancelled by the insured or the insurer. A suspension may be avoided by the return of the registration plate, registration sticker, if not currently placed on registration plate, and registration card to PennDOT at the time the insurance policy is cancelled, financial responsibility lapses, or when the vehicle becomes inoperable for a period greater than 30 days.

From this information it would appear that if you turn in the license plate and registration sticker and inform the Pennsylvania Department of Transportation that your car is inoperable that you will be able to take insurance off of the vehicle. Again check with PennDOT to confirm this before taking insurance off of a vehicle, even if you do not plan to drive it you do not want your registration or license to be suspended for not following state laws.