The 52-year-old actor tricked the 29-year-old actress into believing her 1968 Mustang had been stolen a third time for the show's Nov. 4 episode.
Overhaulin' ran for five seasons on TLC, and moved to Velocity in 2012. The series sees unsuspecting "marks" have their cars, usually old or antique vehicles, spruced up and customized to their suprise.
"Working with Johnny, it was cool because he's such a down-to-Earth guy and he loves the creative process," host Chris Jacobs told Entertainment Tonight. "He can laugh at himself and take a joke."
Depp and Heard met on the set of the Rum Diary in 2009, and started dating in 2012. The couple married in February, and the actress is stepmother to Depp's children, 16-year-old Lily-Rose and 13-year-old Jack, by his ex-partner, Vanessa Paradis.
Depp last appeared in Black Mass, and is slated for Yoga Hosers with daughter Lily-Rose Depp and Alice Through the Looking Glass with Anne Hathaway. Heard will next appear in The Danish Girl with Eddie Redmayne and star in London Fields with Theo James.