These files contains the specifications to each car. They were, by a mistake, released decrypted and then withdrawn. I have a complete set of them here (http://www.thorlaksson.dk/dmw/percy_GTL_CAR_files_v1_0.zip)
According to an official statement these will be released 'later'. However, in order to make your own stand-alone car, being a completely new car with new physics, or just a copy of one car you want to tweak or skin seperately from the others, you have to have this file - since the car number (666 on mine for instance) has to be changed in these files, and being encrypted as standard prohibits that.
Figured I would let you Charlies know about these files, should you want them - they are very hard to find on the net!
Link doesn't work for me.
Sorry - fixed.