Somebody built the car Homer designed and destroyed his half-brother’s business with! It’s a pretty approximation from what I remember of the episode. There’s a movie of the vehicle doing donuts too. Mmm…do-nuts.
Next thing up for the car is a 24-hour endurance race. I wonder what the other competing vehicles will be? The Sixties Batmobile? Bond’s car from Goldfinger? KITT? Speed Buggy? The Mach 5 would be cool.