Mine is now in at the dealer having the work done. Originally I was going to have to stump up a huge amount of cash (about £350 to £400) but after some 'negotiation' with BMW UK, they agreed to pay all but £100 as goodwill.

I'll give some credit to the Service Manager at my dealer who fully understood my annoyance and also spoke with BMW UK.

BMW UK do consider the roof rails to be 'trim' though, and not covered under either the bodywork corrosion guarantee or any AUC/extended warranty, but I think they realise this must be a manufacturing defect as why do they all go in the same place?

I feel a partial result, and just hope the dealer doesn't cause more problems by having to rip the headlining out!

Same problem on my '06 X3, dealer replaced the roof rail.

My roof rail is now all sorted. Dealer did a good job even though I did have to pay 20% of the labour cost which ended up at £97. Am relieved it's been done and now just have to get the transmission and climate control panel issues resolved that the workshop can't diagnose (been in 6 times for these!).

Interestingly, after a chat with the SA, he tells me that this problem with the rails is common on both the 3 series touring, and the X5! He claims it IS a manufacturing defect that BMW know about and that it's a failure between the joints allowing water to get between the bits of the rail, rotting them from the inside out.

As I got absolutely nowhere with BMW UK finally took the plunge and got one of the local smart repair centres who do scratch repairs to sand them down and paint them in a matching paint finish - looks brand new - only cost me £ 70 so very pleased