Recommenadtion for a service in Hertfordshire?

[simon920]

I have a 2002 C230K coupe. It has now covered 37,000 miles and is telling me it needs a "B service". Can anyone give me any advice on a good bet for a garage to get the service done around the Watford / Herts area please? This is my first Merc and the first time its needed a service, so am learning...!!

Also, should it be main dealer or is specialist alright? The car is 5 years old now, so would MB specialist be OK?