I can tell you this: If you are pulled over driving in the city of Philadelphia, and you don't have CURRENT and VALID driver's license, registration, AND insurance coverage (ins might not be enforceable for out of state car), then your car WILL BE TOWED AND IMPOUNDED. It's called "Live Stop", and when the wrecker pulls away with your car the cops leave you to walk wherever it is you need to go. You don't get your car back until you can provide valid documents, and pay the fine/impound fees.
I can't say anything about your license, but I imagine it isn't all that difficult to see if the registration is valid, even if out of state. Hope that trip doesn't include driving in Philly.
