GMP CARS, LLC GMP Cars is an alliance of automotive services including mechanical repairs, collision repairs, refinish and restoration services flowing together under one roof and offering customers a one-stop-shop experience. Our extraordinary team of carefully selected experts specializes in quality maintenance, precision restoration, and high-end enhancements to the finest cars in Northern California. We provide exceptional customer service experience to our customers. GMP CARS currently has 8 locations with a head count of over 160.