Bill Whipple is Jim MacDonald's happy-go-lucky mechanic, who thinks that he is the world's greatest driver and lover. Mac has treated Bill like a son since he took him in. One day at the track, Bill sees the lovely Pat Bannon, and tries his best to impress her, but to no avail. On his way to catch a flight, he tricks Pat into taking him to the airport, and she gets even by taking him up in a plane. He hates to fly, but will not show her that he is afraid, and when the plane breaks up, he is a hero for rescuing her. This gets him publicity and Lee Renny offers him his car to drive in the Indianapolis 500. Bill breaks with Mac to drive the car and puts it on the pole for the race. Then Renny double crosses Bill and drives the car himself since Bill has tuned it so well.