Haven't heard of any in Salisbury.
The closest would be either MBS Southampton, or Hamilton AutoTech in Corfe Mullen Dorset, both of which I would recommend.
Pentangle in Totton look after my W204 - even though I now live in Mid-Wales I still drop the car into them for work when required. I find them very knowledgeable and courteous, and they always give me a courtesy car. Their hourly rate is £65.
Thanks all. I went to Hamilton AutoTech on Tuesday and was impressed by the service I got. Great guy, very straight, knows his stuff, and only £50 per hour.
Definitely will use him again and thoroughly recommend him!!
^ Glad I'm not the only one to appreciate the service Richard gives at Hamilton AutoTech.
It's a small set up but as you say, he is very knowlegeable about the brand.