In each level there is a Secret Car that can be found.
Level 1: Go to the rich neighborhood and drive to the Gold house. In front of it there is a rocket car. Homer can drive in it at high speeds but watch out, it can be destroyed very easily.
Level 2: Go to the Monorail station and walk up the stairs. When up the top, go to the first car of the Broken Monorail and get in it. You can now drive the broken Monorail along the roads.
Level 3: This is the only car that I can't give a description of. But I know it is Knightboat. Find it around the bay.
Level 4: This car is actually a four-wheeler Motorbike (Quad bike). Just go to the Trailer park as Marge and find near a caravan. It is fast but very hard to handle.
Level 5: Apu's Special Car is very easy to find. Just go to the Springfield Stadium and on a large platform, there will be a Monster Truck. You can get in it a demolish anything you may find! Mwahahaha!

Level 6: Go to Planet Hype's Roof and fall off just a bit, so you fall on the pink Cadillac that is stuck onto it's wall.
Level 7: Climb on the Tankers and Fire Trucks to reach the Roof of the "Spooky Burger" next to the "Spook-e-Mart" and on top there wil be a Toy RC that you can actually drive.
