Dempsey told Parade magazine he ran into "Transformers" director Michael Bay at a Ferrari event and offered his services, which led to a role as a car buff investment banker in this summer's "Transformers: Dark of the Moon."
"I knew that there was a character that was possibly right for me so I brought it up -- and this was in the midst of talking to some former F1 drivers and other drivers that I drive with," Dempsey said. "It was the perfect place to meet for this character."
Dempsey, a regular on CBS' "Grey's Anatomy," told Parade he didn't get a chance to do any driving in the movie but loved the cars and the whole action-packed extravaganza.
"I'd never been involved with anything quite like it and loved every minute of it," Dempsey said. "I had probably the most fun I've ever had on a movie."