Thanks to Phil of www.philsfiles.de, who brought us KITT for GTA3, we now have KITT OR KARR for Grand Theft Auto: Vice City!
The mod replaces the Zebra Cab, which you get after you finish the Kaufman-Taxi mission. Once you complete it, you will find the car waiting for you at the aufman Taxi Building! The car doesn't do any of the features of KITT/KARR, however after you complete 100 Taxi-Missions you will unlock the ability to jump with the cab, and thus KITT or KARR.
You will require the following files, plus the Vice City game for the PC only to complete:
and finally:
Remember, this is a mod, and you perform it at your own risk!
Thanks to K.I.T.T for the heads up!