Is there any way to put decals/skins on a vehicle that does not already have a decal/skin?

As long as you got the template you can pretty much put whatever you want on it.

 

Edit: Like, lets say you have a unmarked car that you wanted to make slicktop...yeah, you could make a skin for it ...But you gotta need the template for that specific car....you also have to have photoshop, paint.net (it's free) or some other photo editing software to change it.

Edited August 17, 201510 yr by MasterTrooper
Added responce

If you mean a full texture on it then no, it will have to be UV mapped first, but that is possible now so look out for it.