I've owned a 2008 CLS 550 and now own a 2010 CLS 550. Both cars had brake squeeking and heavy dust build-up issues. Mercedes says this is normal. I was real tired of cleaning my rims every day and hearing my brakes squeeking all the time (embarrassing for an $80k car). I spent $400 on ceramic brakes...best investment! Rims stay clean and brakes NEVER squeek! Wanted to share this with you guys!