Hello,
I just thought I would post this in case anyone else had problems with the cheat to make all cars in the game Stealworthy instead of just the nine that are available. Simply run the GOG version Carmageddon as Administrator (if you dont run as Administrator it wont work) and type "IWANTTOFIDDLE" after you load your save game, you should hear the sound of tyres screeching, then exit Carmageddon. Now go to the Carma/Data/Cars folder and you can now edit the .txt files for each car, open a file and change the "not stealworthy" line to "stealworthy" then save the file. I have not experienced any bugs or crashes doing this.

I Hope this is helpful :)

EDIT: Every car still requires a certain level of reputation to steal.

You know, I found something interesting. In Splat Pack, Annihilator II (Vlad's car) is not stealworthy by default, but unlike others, it doesn't have the "CHEAT!" banner. Maybe originally it was supposed to be stealworthy, like original Annihilator from Carmageddon? Annihilator II uses original Annihilator's interior, unlike other "not stealworthy" cars - they have (sometimes glitchy) Eagle interior.