Is it price, there not that expensive. They definitely help keep your wheels clean & definitely no noise or squeal!!!!!
I have them on the front & rear of my car for 3 months. MY WHEELS NEVER TURN BLACK & I''LL NEVER GO BACK TO METALLIC!!
http://www.bimmerzone.com/BMW_Parts.htm
N1010-186512 Brake Pad Set EURO Ceramic w/ Shims Akebono IN STOCK $67.53