Steve Bostock, who has countless concours trophies to his name, has started a detailing company called A2D (Attention to Detail) and he's very good. BMW Car magazine did a feature on him and his amazing collection of cars 3-4 months ago.
Can also get pin dents taken out whilst the car is with him and sort minor paint blemishes.
Close to M1 Junction, 07811 722742. Well worth a ring if you want it done right.