Last year, NASCAR driver JEFF GORDON pranked a used car salesman by taking him on a crazy test drive.  And some people thought it was staged, including a guy named Travis Okulski who writes for the website

So recently, Jeff tried to PROVE to Travis that the last one was real . . . by posing as a taxi driver, picking him up, and then leading the cops on a HIGH-SPEED CHASE.  Of course, some people think this video was set up too.

WARNING:  Bleeped profanity and "a**.