Hi,
I have a 97 M3 and I have an Eclipse head unit, model 54410,m I love it. Eclipse is the top of the line head units, they are not sold in best buy, circuit city, etc, only top end stores. The one I have retails at tweeter for $279, but I got mine off ebay for $120, check out ebay for a good deal.
www.eclipse-web.com
Rob