I recently purchased a '68 GTO from a guy who bought it from the original owner just to flip it and i'm told that makes it a 3 owner car, which doesn't seem quite right to me, but anywho, i just met with the original owner who just found his paperwork and protect o plate when he bought the car. He has said that the car is an unmodified original, except one lower quarter replaced back in the '90's, and a period correct AM/FM radio installed. I thought i'd read, or dreamed somewhere that a protect o plate is the absolute ONLY way to tie the drive train together as original to a car, and not just period correct. And that PHS documentation doesn't prove it. I've researched online and don't find the definitive answer. So, does the POP do the job? Hotrod.com has a decoding series, but even they weren't sure that the code next in line after the engine code was related to the transmission or not. And certainly there doesn't appear to be anything codelike for a rear end. I searched the forums and the latest posts i saw were 3 years ago, and apparently some of the online info available now wasn't available then as far as decoding. Can anyone weigh in on the POP? Thanks.