[darrin]

I'd be concerned with the ramifications of having a tag for another vehicle on your car, even if the cars were similar (especially with the police's widespread use of automated license plate scanning technology that could create a "hit" if, say, colors were different) -- seems verifying VINs is relatively routine when pulled over and putting your existing tag on the new car could open you up to some significant issues.

The signed-over title, completed and signed bill of sale, matching ID and printouts of docs from GA referencing how the state doesn't issue in transit tags and PA's in person VIN inspection requirement should get you through any potential LEO encounter by showing that you did your homework and are complying with applicable law. As a seller, I had a real concern with giving my plates to a stranger/buyer (and the attendant representation that the stranger's actions were mine/ratified by me)