Abbreviation of Georgia Marketing Promotions, a company that makes model cars and accessories. Gmp is most famous for making 1:18 scale models of Fox-Body Mustangs. They are very expensive but worth it.
Did you see the '93 Cobra R by Gmp? Its amazing in every detail! The rear seat delete, functional seat belts and realistic engine plumbing. At $100.00 its so worth it!