I had occasion to use Mototune of Blackpool last week to run a tune up on my 200T. Absolutly fabulous service. Total diagnostic check and advice on how to rectify problems found. Also told me how to effect a mod to my distributor drive. The cost for these, £51. I was dubious at first using him, but looking in the garage there was a 230 Kompresser and a SLK, along with a Z1 BMW and other sundary quality motors. His phone number is 01253 696206 and ask for Rick the Merc man (ex Mercedes Blackburn). He will offer advice over the phone.