If you look inside, there is a man (proberly alien like) inside the car. Most of the time, the player has to race the car in missions. The car is looks the same as Bart's Ferrini Red except it has a purple hue and has a roof, you can't open the doors,
Appearances: "Long Black Probes", "There's Something about Monty", "Alien "Auto" topsy Part II" & "Alien "Auto" topsy Part III".
How to Unlock
It can only be obtained through a cheat in the game.
Its a 100% Feature that you can drive when you achieve 100%.
How to Unlock (PS2): Get all Gags, Wasps, Street Races, Missions, Bonus Missions, Clothes, on every level then enter the bonus cars code which for ps2 is Hold L1+R1 then XOXO then enter a phone booth and press l1 and scroll through the secret car list till it says Ferrini - Black.