Jacksonville Buick GMC Car Dealership. Nimnicht Buick GMC sells new and used vehicles, financing, automotive repair, parts. Online auto loans and shopping. Serving Jacksonville, St. Augustine, Orange Park, Florida to South Georgia, Brunswick, GA 16,231 When you arrive at Nimnicht Buick GMC in Jacksonville, Florida, you'll find an extensive new vehicle inventory of Buick and GMC trucks, and SUVs. We also offer a vast lineup of used, certified pre-owned and Luxury pre-owned vehicles.