If you are picking images from the net and reworking them you are probably going to step on toes. If you own or know the owner, just ask for permission. These car buffs may like their pride and joy be a commercial success. I print private party rods for them all the time. If you don't know the folks, best get the royalty free images and check the license agreement that usually accompanies it on the CD or at download time. Car shows are great for new images... Just ask the owners. Ya never know.