Let me add info on drive from Germantown to Clarendon VA:

I drive from Rockville to Clarendon everyday after work.

Time can vary from 30 minutes to 1 hour (or more). And it depends on the day of the week. Normally with traffic moving - it is 30 minutes. Add another 15 minutes if coming from Germantown - plus any extra time you need to get to I-270. Yesterday (Tuesday) the drive time was 1 hour from Rockville to Clarendon - due to major Beltway delays. In these cases - I exit and use Seven Locks Road from Democracy Blvd - and proceed all the way down to MacArthur Blvd and re-enter the Beltway at the American Legion Bridge at Cabin John.

From Germantown on a Tuesday - I would allow 1 Hour and 15 minutes. Rarely longer (but hard to predict).

Parking - you can not park in the residential neighborhood. Meters open at 6pm in Arlington and there is free parking at Arlington County Building at night and is/used to be at the Hud building at Highland and Wilson - off Highland, just north of Wilson. Of course there is pay parking at the Market Common Center.

As pointed out - you need to drive all the way down GW parkway - go under Key Bridge (do not exit at Key Bridge) - but take next exit and go 50 West. Be careful you go right after the exit or you will wind up on Roosevelt Bridge and be headed into DC.

Go Right on 10th, then sharp Right on Fillmore and that will take you right over to Wilson at the Wood Grill. If you miss the sharp right on Fillmore - you will go right onto Washington Blvd - then cut over Garfield or Highland then right on Clarendon Blvd - past Whole Foods, then next left and backtrack (left again) on Wilson.