1st LEVEL - Rocket Car outside (close to) Mr.Burn's Mansion.
2nd LEVEL - Monorail - The First Car of the Broken Monorail System.
3rd LEVEL - Boat - on the big cruise liner inside the green box.
4th LEVEL - 4 WHEELER - On the left of one of the trailers in the
trailer park.

5th LEVEL - At  the stadium jump from the fountain up to
the Monster Truck.
6th LEVEL - DONT KNOW I HAVE YET TO FIND IT.
7th LEVEL - NEXT TO THE BIG ACCIDENT ATOP THE KRUSTY BURGER IS A RC CAR