Look at the Product Info Guide posted as a sticky. It has all the info on this. I thought about waiting for the xi in the fall, but pulled the trigger on a car (specs below) with SP with expected del. July 30 or so. I live in the Midwest and we get a fair amount of wintry mix/snow/ice in the winter. I'm going with the winter wheels/tires. The problem I had with the xi is that if you get the SP, you get the seats and steering wheel, but you also get style 158 17 inch wheels. I don't like the 159s or the 158s, so the tire/wheel upgrade of $600 additional was going to be my route to get the 18 inch 162s with larger tires. However, then I'm back to snow tires/wheels ANYWAY, since regardless of whether 4w or 2w drive - summer tires do not grip. Soooooo, saved the money and time and got the rwd.
330i/TiSilver/Black Leather/Step/Poplar/Prem/Sport/Cold Weather/Navi-Idrive/Sirius