I have used spacers on my MB for a wider stance and the (Brabus) wheels required them.
I think that it doesn't look good to get a wider stance without lowering the car though.
When lowered, a wider stance definitely requires you have a wheel alignment with the proper camber adjustment or you'll wear out the inside of the tires even faster than when just lowered (in 5k miles or less).
Also, you must use hub-centric spacers or your car will vibrate and give you a very poor ride.
Last edited by Wolfman64; 11-17-2012 at 12:52 PM.