After further research at Tire Rack, it looks like a mistake to go with 17 inch wheels, at least with the M235i. There are quite a few more options in snow tires with 18's. Unfortunate given that going to the smaller size is almost always the better option for a set of winter wheels and tires.
Oops, scratch that. Only two run flat options available, one is discontinued and limited availability, and honestly, I don't want either choice
