If you're coming down 270 from Frederick to 95/495 (the Washington DC beltway) then following 95/495 around the north end of the beltway to the east side will not be that far out of the way. You could hit the place Jack mentioned, or check out Speed Unlimited in Morningside, MD (not far from Andrews AFB).
https://shop.speedunlimited.com/
https://www.google.com/search?q=spee...hrome&ie=UTF-8