We just got our new 328i Convertible back from the dealership after a smooth ED process. It is our first BMW, and our first convertible, and we are completely in love with the car.
After quite a bit of research on this and other message boards, we found the name of Joern Esser @ Passport BMW (MD). Joern quoted us $1500 over invoice, which we found to be a very reasonable price.
I can honestly say that this has been the easiest and most enjoyable car purchase I have made. I can wholeheartedly recommend Joern (and the ED option).
(I wish I knew how to post a pic on here... but oh well, ours is a E93 328i TiAg / Coral / Gray Poplar.)