In the US, the only BMW run driving school is the Performance Center at Spartenburg, SC. They run 1 and 3 day car control schools, the 2.5 day M school and the Advanced M School. They also run teen driver programs and a special 2 day car control for women only (instructors are women also).
There are a bunch of good commercial driving schools around the country. My favorite for beginning performance drivers is Roos Racing (
www.racenow.com) and their 2 Day Precision Highway School. Very good stuff that you will use every day. They run at various locations, but home is Pocono, PA.
Others that have non-racing oriented courses are, Skip Barber (
www.skipbarber.com), Lime Rock, CT and other locations, Bob Bondurant located in Phoenix area.