Hello,
A local indy shop that has earned my business is Curry's Auto in Sterling (
http://www.currysauto.com), directly off the Greenway. Their lead Mercedes tech (Ryan) has been a great resource while I transitioned into the pre-OBD2 DIY world. Experience has been just as satisfactory with the wife's Audi.
According to the corporate website, a new shop has recently opened in Falls Church (105 Falls Ave.). They charge a fair price compared to non-specialty shops and offer a 5% parts discount to local Mercedes club members. Give their shop a call with your to-do list, and let me know how the service turns out if you choose to do business.
Regards,
DM