Well Fred it was a rental car. He should have turned in the keys at the airport and ended the contract instead of holding onto the keys and not ending the contract. (I think I just repeated myself!! ) But that is the reason Columbo suspected something was wrong.
Good posts. What really makes me laugh about this episode - is the concert scene. Notice what Johnny's character and his wife do with their arms. They look like they're having a "fit" or something.
I also liked Sorrell Brooke in his mod glasses and talking hip. Quite a change from his role as "Boss Hogg".
I've read (I think in Goofs) that this episode interspersed some real footage of a Johnny Cash concert. June Carter Cash certainly could or would have been one of the singers. Now I have to go home and watch it again to see for sure.