I had this same problem when I purchased 18" winter rims & tires for my 2012 750li xdrive Msport from a guy here on bimerfest (great deal and solid transaction). The tire pressure sensors weren't right so I had to spend an extra $500 when they mounted the winter wheels for new tire pressure sensors. (owell)
I bought the rims/tires because you can't put winter tires on 20" rims. The 18" rims/tires came from a 2009 bmw 750i I believe.
Last edited by sdadept; 04-24-2013 at 12:59 AM.