I have been there and Rockville. Rockville has a new facility as they just finish that about a month ago. I personally like the Silver Spring location better more down to earth people and not as stuck up but that has been my experience with that group.
20% on the side and rear little glass window and 5% on the back rear glass. Owner before me did this. I am on the fence about the rear glass because it looks completely black. you can't see the engine bay at all.