Well, half true. The Boss/most AI cars indeed have Unique Texture Vinyls, which aren't modifiable.
But, as Decals can be Placed on Windows, Vinyls can be too (with a little hex-editing)
As both Vinyls and Decals use the same Codes, they're interchangeable.
The only difference is that Decals have just one Color instead of four and are placed over Vinyls (and Windows).
Some Boss/AI Skins are available as normal Vinyls, too.
See there:
http://forum.nfsunlimited.net/viewtopic ... 00#p326269
Racing M3 GTR wrote:I know it's possible to put vinyls on part of the BMW Z4's side windows plus the front windscreen of the '04 Pontiac GTO,
Yep, some other cars have these 'vinyl placement issues' too. That's a very annoying bug, imo. Can't put Vinyls on the Door of the Z4, but the Sidewindow. Great.
Changing Vinyls to Decals in Savegame is alot easier than modding other Game Files, as most things in Savegame, especially the Cars/Blueprint Part is already known.
uncovered?unveiled? bah my english sucks here
Any more questions on savegame-editing? Feel free to ask.
(after reading around in the above linked thread, maybe it's already answered there)