there's been two things that did Petty Racing in.
1. he just now built himself a a new shop. just now. i don't know if anybody had ever seen the old Petty show, but it was a dump. don't get me wrong it's probably an incredibly historic shop but by today's standards it sucked. i'm not sure why it took a bajillionaire like Petty so long to build himself a state of the art shop.
2. the most important reason. Adam Petty was going to be a superstar. it's shame too because NASCAR has no business being at that dump snoozefest race track in NH anyway. when Adam was killed, so too was the Petty name. that's not to say that they can't get back to the top, but they took a major blow when they lost Adam. it still upsets me sometimes to think about it.