tertius said:
Thanks all. I have actually used CPCPE, and whilst I agree they are very good, they seemed glacially slow, and although I was happy to use them again, I have rung four times now, left a message with a human being every time, and they haven't bothered to ring back, so looking elsewhere.
I wouldn't trust anyone else with my car - I also drive from SW London to Amersham (although it helps that my parents live in a field not too far from there). Often Phil picks up his kids in the mid afternoon, so before 0800h is the best time to call if you want him in particular.
I used AMC once too, but only because my car was stuck in limp mode and 40 miles at 20mph wasn't a realistic proposition. I wouldn't go there again as they were expensive and (as said) totally impersonal.