Wow! I agree. Take it back to the dealer.

Somethings amiss, after driving through several salted road winters the rust on my calipers/rotors is nothing compared to that - go back to the dealer.

You didn't go for a quick spin in the Bognor waves by any chance ;)

Based on that level of corrosion, someone has used some wrong chemical to clean the wheels/calipers. I've never seen anything like that before.

I know of someone that had his calipers replaced under warranty because of this problem. It was on an X5 in the UK.

Are you using a lot of alloy wheel cleaner on the wheels, and quite frequently ???

Some brands of that stuff will strip paint !!!

she going in next week, the dealer has agreed to replace them

Mine are rusted too, not that bad but they are rusted. I guess I'm getting new calipers.

Straight to the dealer!

For what it's worth. BMW does not put paint on it's calipers or hubs (?) (the part between the wheel and rotor). I found this out when I changed out my wheels exposing the system behind the stock wheels. I talked to the body shop at the dealer and he proceeded to show me the owners car. Same problem, light layer of rust. For $133. they painted the calipers and hubs silver. Man told me no guarantee and after looking at the calipers I know why. Quick cleaning job, not thorough. There are now two cans of caliper paint in my trunk and as soon as I have some time to get it into a shop I've used for years it will be properly done. Google "painting calipers". There are numerous ways to do it. Some even suggest powder coating. Problem with that is calipers have to be removed and taken apart. Car would probably be down for 3 days at least. I've owned Mercedes and Porches. They paint there calipers. Cost cutting?

When it is time to replace the rotors look at Centric. They are good quality rotos and they come with a black coating on teh hub that stays clean looking.