Notorious prankster George Clooney recently enlisted the help of John C. Reilly to pull a fast one on Perfect Storm co-star William Fichtner.

Clooney came up with the idea for pranking Fichtner after weeks of listening to the actor brag about his beautifully restored classic muscle car. Even Reilly, who owns a 1968 Chevelle Malibu, was getting tired of listening to Fichtner carry on about his four-wheeled baby.

At Clooney's prompting, Reilly made up a story on the Perfect Storm set about how his own Chevelle was leaking transmission fluid all over his garage at home. Then Clooney arranged for one of the stagehands to get some transmission fluid, bring it back to the studio parking lot, and pour a huge puddle underneath Fichtner's classic car.

"Bill came out and he turned ashen," recalls Reilly. "You know, when you see transmission fluid, that means something really bad has happened.

"Mercifully, [Clooney] didn't allow Bill to take it to the shop and tear the car apart and see what was the matter, because people started laughing before we could let it get that far," he says.