Hey folks - I know you are having a hard time trying to find winter wheel and tire packages for the F15's. If you are looking for a low cost option to get you through the winter, feel free to take a look at my winter wheel and tire package I am selling. 19" Pirelli winter run flats on the Tire rack wheels, which are sold out. Buy this set for about the same amount the tires alone would cost you.
E70 and E71 wheels all fit the F15.
The TPMS aren't compatible, but that can be easily changed. Or deal with it and unload the set next year if you upgrade to a different package.
Here's the link to my for sale post:
http://www.xbimmers.com/forums/showthread.php?t=935005