Todd Neiss camouflaged his 1979 Chevy K-10 Blazer using real plants as stencils. He calls his vehicle the "Squatchmobile." From Cryptomundo:
I would spray the color (flat) I wanted for [what] plant first, then lay the plant over the paint and spray a background color over it. I intentionally arranged ground plants low on the body and trees on the upper half."Cryptocamouflage Vehicle"
The whole truck took me two days. Technically it is a work in progress as I carry cans of paint with me in case I run into a plant I haven’t captured yet.”