No surprises and no guesswork. Having your vehicle serviced at Wheaton Pontiac Buick GMC has several advantages: Specialized diagnostic equipment. Factory trained technicians. Genuine GM parts. Menu pricing. Our services are menu-priced and follow the General Motors Goodwrench Service guidelines to ensure the proper service intervals are simple and easy to follow. Regular Dealer Maintenance is the best way to ensure the highest possible value at resale time and give you piece of mind ownership of your vehicle.