Thanks for your reply - don't I have to use a main dealer for servicing to keep the warranty valid or has this changed?
First of all, do not pay that price at AMC Chelmsford! Total daylight robbery!
Secondly, no you don't have to take it to a dealer for servicing to keep the warranty valid. As long as the car is serviced to the correct service schedule, the garage is VAT-registered, and the parts used are genuine Alfa Romeo parts, or parts of an equivalent standard.
Having said this, I do understand the desire to keep with the dealerships for scheduled serving in the first three years. Somehow there is peace of mind involved, you know the correct schedule items will be done, and in the event of any problems warranty-wise you know the situation is 'copper-bottomed', despite all that's said with regard to the law. Also, if any warranty works need s to be done at the same time as a service, this must be done at an Alfa dealer.
I would suggest you travel a little further, get a quote say from Donalds in Peterborough, mention you're a member on here, you should get a discount off the quote. But whatever you do, don't pay that silly and insulting price at AMC Chelmsford! Ugggggghhhh!!!