I did a search but couldn’t find where this has been discussed on here before. Happen to turn on the TV after work yesterday and Andy Griffith was on.
February 5 1968 season 8 episode 22 “Goober Goes to the Auto Show”. Wasn’t expecting to see a Cougar so didn’t get a real good look figuring they would have a Mustang & Ford products. Appears to be Madras blue & white interior with wire hub caps. They panned over a back of a display engine that could have been a 428CJ but didn’t get a good look. WIKI said the hot dog salesman is Johnny fever from WKRP in Cincinnati. Only picture I found that you could see some of the Cougar in the background.
There’s a website called IMCDB, the Internet Movie Car Database; it’s a great place to find stuff like this. Warning: you could spend hours browsing here 
Classy looking car!