www.scuffsnstuff.co.uk in Markyate (Junction 9 M1) did a good job on a car park mark (damn you white people carrier!) on 154 before. Its a ways around the M25 for you, but they are open Saturdays and their prices were good.
Awesome, the guy near me got techinician of the yr 2003.. I only have some small dents - they just make me so angry! I also managed to lose grip of my door and dented my mum's car so I should get that sorted before it's sold - d'oh!!!!!
Thanks for the advice - I can't believe they managed to remove your dent!! 8)