Since the market for our cars is so new, it's probably going to be easier to see what works on a GLA. Those have been around for a few model years now.
I was going to start looking at MB wheels and seeing how much I can pick up a used set for. I think the QX30 wheels are ugly and I spotted a GLA with some AMG 18 inch rims that were way better. It might be difficult to find a set, though. There are some on ebay right now for $1600 + $600 shipping from Germany!
I don't see many GLAs in Oregon. Actually, I've only seen about 6-7 since I bought my QX30 and I've only seen one other QX30 on the road.