Mike, I don't think Advan RS's come in 20's. I've seen them in gunmetal on a sapphire metallic e90 330i with M3 conversion in silver. Go with the gunmetal. It will look much nicer. They are great performance wheels because they are 1 piece forged wheels, are very strong, and don't weigh much. They will greatly reduce unsprung weight and be a big difference performance wise from your other wheels. Your handling and braking would greatly improve from 20" DPE's. I would only go with the Advan RS if you like the JDM style on a german car though. IMO Advan's only look good with a very aggressive offset with a stretched tire...
Here's a link to the sapphire e90 from the car show i went to. It's magmd's car with the silver Advan RS's: Just scroll down:
http://www.e90post.com/forums/showth...ight=eurocrave
Here's gunmetal Advan RS's on a black e92:
http://www.e90post.com/forums/showth...ighlight=advan
PS: checkout a quick photoshoot i did yesterday when i was bored in the pictures section.