I wonder whether the 18-month-old Polo that needed new front discs and pads after 8500 miles really needed them? In my experience the worst people for try to sell me unnecessary things during a service are my local BMW garage. When my X5 is in for a service, they ALWAYS ring me with "It needs... " etc. I consider their policy to be less than honest. During one service, a young woman rang me and said "Your car really needs rear brake pads.. .there's only 3mm left." She then quoted a price that I forget the exact amount, but it was close to £200, which I declined. This surprised me because, as the pads are quite visible through the alloy wheels, I regularly have a look at them. When I went to collect the car it was parked outside so I had a look at the pads before going inside to reception. The pads looked less than half worn and when I questioned this with the service assistant she told me "3mm left" actually means 3mm left before the pad gets to the BMW recommended thickness of 3mm…ie "your pads are 6mm thick" (which is four times the thickness required by MOT test). I also pointed out that when the pads are wearing down, a warning light will come on, presumably at BMW's 3mm limit. As I'm sure you're aware, this practice would frighten most people into saying "Replace the pads now" but I suspect no mechanic in his right mind would throw away 6mm brake pads off his own car. And finally, to compound the situation I was given a bit of a lecture on the dangers of carrying out my own repairs (I am a 62 year old retired mechanical engineer/petrolhead who has rebuilt most things from mopeds to Jag and Aston engines). I did mange to remain polite.