Plenty of shops both South and West of DC. All these guys are very good.. your choice!
Paul
http://www.tagmotorwerks.com
Gaithersburg, MD (Ham) (301) 258-0859
http://www.stuttgartperformanceengineering.com/
Gaithersburg, MD (Matt) (301) 948-6762
Autosportsystemsgroup
Merrifield, VA (Jeff ) (703) 876-2811
www.imamotorsport.net
Fairfax, VA (Ivan) (866) 434-4838
Intersport - Porsche, BMW, Mercedes, Audi Service & Repair
McLean, VA (Omar) (703)-242-8680