ok i have no problems exracting the stuff from decal.bin and i can pack it back up but when i try to use the decals the xbox freezes and when i try to paint the decals i want directly on the car the dont show up or it says the design is corrupt...

Try clearing ALL Cache and I cant put the design directly over the car either so dont feel bad.

another solution could be from you editing the decal completely wrong such as erasing or somehting such as that...