On a ride the other day. Coming to a stop. The rear brake besides the rattling disc squeals and emits a metallic groan. Upon inspecting the pads, which are half worn. Plenty of meat left. Upon inspecting the disc. I found it moves side to side as before,crappy BMW disc. Now moves front to back. After inspecting front pads. Their fine. So my guess is it's a worn out rear disc. My question is. Where's the best place to get a EBC rotor. Beemer boneyard has them for like $185.