Anyone know as I feel a major whinge coming on? Just booked mine in for its cambelt change and mentioend that the expansion bottle has gone brown since they last serviced it. Their reply? Its a problem with the oil cooler that causes it !!! My big issue is that there was no reason for the coolant to be touched in anyway, but a mechanic mate, actually he builds indy car engines for Judd Racing so he knows a thing or two, he had a look and said it should be pink and not clear with water like qualities. Water only as a coolant would cause the browness he said, and due to his techincal background, I believe him. Am I sceptical in thinking that the Audi dealer that serviced my car repalced the D12 with water?