Nevermind, found the answer myself...
If the so called "VOB mod" keeps within the original hitbox of the car (like a better model of a car that resembles one from LFS) why would these be a problem?
For example, a Civic Hatchback VOB would easily fit within the XFG hitbox...
ALSO: Not trying to encourage or entertain use of these, as I don't use any myself, just curious as to what is so bad about them... It's like the darknet of LFS.