I'm in west London too but of course, being a large area, where I go may not be convenient. Lookers in Hersham, you can book a timed slot and wait for the car which helps. Been using them for 8 years and they are pretty good. Unlike others say about their experiences, they don't try scare tactics with disc/pad wear to get more £££s out of you, in fact in 80k+ miles across 2 cars they have never given any warning on brake wear.