J.C. Billion GMC Buick in Bozeman, MT | A Billings, Butte, & Helena, MT Buick & GMC Source J.C. Billion GMC Buick in Bozeman, MT also serves customers from Billings and Butte. We offer new and used vehicles, as well as parts and service. Come down to our auto repair center in Bozeman, MT today!