Cars

"Cars" is Episode 12 in Season 4.

Synopsis
Sam has had his old car named Gertrude for so long and it's time to get a new one. But Gertrude is special and he is sad that he has to give it up. So he goes to Smiling Jack's used car dealership to buy a new one. And Muffy overhears Smiling Jack say that Gertrude is going to the junkyard crusher. When Sam tries to get it back, he learns that Jodie bought it back for him.