Question about logos

Lets say i got a finished car in 3dsmax, i mean with the paint material APPLIED, and i want to put some logos over it, must i use Unwrap UVW map or there is other way to do this?
You could just model the badge...personally, I always model badges because I find it alot less work than having to apply 20 textures just to get it to work over different paint it looks 100x better. ;)
In this case im not talking about badges (since english is not my native tongue maybe im not being very clear, sorry 0 :roll: )
Im talking about, you know, racing cars have a lot of publicity on them, numbers and other stuff with alpha maps, well, those things :lol:.
Is Unwrap UVW the only way?