[raven333]

Well here is an update for those who maybe interested??
Took my car to the selling dealer, they put my car on the ramps and removed all of the wheels.
They said that compared to other cars which they had on ramps, mine was in very good condition compared to other models either younger in age or relative mileage. So I went into the maintenance area and looked at a range of cars including a 6 series on a 2011 plate. The level of surface corrosion was appalling !!
What a mess each of the callipers where on the other cars, in fact I could not believe it unless I saw it with my own eyes!
They were implicit that the major cause of all the corrosion was the chemicals people use to clean their alloys which causes rust everywhere else, but they class it as surface rust!!!!
They showed me all of BMW bulletins on the issue.....
My comment was that my car was owned by BMW not someone else as a company car!!!!
So in highlighting all of this I have to admit something here !!!!! When I stripped all my wheels off I cleaned much of the encrusted rust of with a dremel in doing so I sprayed the bare metals with a special spray ACF50, WOW what a difference this has made, everything was covered in bright orange rust before I used this spray and when I got to the dealers I thought the car would clearly look the same..... how wrong I was!!! clearly you still had the result of corrosion ie damaged surfaces BUT there was no rust, no colouration etc.. completely sealed. So the head mechanic was looking at me like I was some form of nutter!!! In fact he knew I had used something....and commented.
Anyway it is not over yet as there is still corrosion on the inner wheel hubs and wheels but the rust is no longer active,,,

Finally what it did tell me is that the BMW callipers are very very prone to rusting and becoming unsightly, secondly no way in a million years will I use any other than BMW wheel cleaners....