I think Womble used to have his car serviced by these people, but I don't have any info on their credentials for 260 knowledge.
http://www.emglondon.co.uk/find-us/epsom.shtml
There is a thread on here somewhere discussing grage recommendations, I will try to find it and post the link.
I have my car serviced by a small independent garage in Dorking, the guy is not a 260 expert but does a good thorough job and is always open to suggestions etc..
Nich.
PS. Just found this from an old post: