Here are the Unlockable vehicles that shouldn't even be in the game at all.
Fire Truck: While the Novelty of driving a fire truck is cool at first, it quicky fades away. This vehicle does have 3 stars of speed, but the acceleration is so low, it might as well only have half a star.
Moe's Sedan: Moe never drove this car anytime in this game, not even when his car was called in a level he was absent in, and it's a pretty crappy race prize (In visual quality, but not stats), so it should've just been left out.
Book Burning Van: Reverend Lovejoy doesn't appear in this game at all, not even simply having him walking around the church in levels 1 and 4, so the inclusion of his Road Rage vehicle is rather questionable.
Clown Car: I understand that this car was in Road Rage, but Krusty's Limo was already in this game, too similar in appearance, was in an actual mission, and unlocked in the same level!
El Carro Loco: It's interesting that this car has pink neon, when none of the other cars have neon under-glow, but Bumblebee man never drives this car anytime in the game, and it never appears in any missions, so the inclusion is kinda dumb.
36 Stutz Bearcat: I like the classic car look, but Monty Burns, who owns this car, never drives it at any point in the game. We already have Mr. Burns's Limo, albeit Waylon Smithers Drives that one.
Hover Bike: This vehicle, despite its stats, is a hugely overpriced piece of crap. Seriously, why did we get this 1000 coin scrap-heap instead of the Ferrini-Black? This vehicle is so clumsy and it never appears in any mission at any point in the game.