Can anyome tell me the minimum thickness on the front discs of a 3.0l SEi. I think they start out 23.4mm thick. Mine are down to 20.2mm. BMW told me I need new discs and pads on the front. I found it funny that my discs have worn out before the 'Low Disc Pad' warning light. And on 31000 miles i just think it is a bit early. I was told over the phone that the work 'Had to be done' I said 'No.' When I picked the car up they didn't give me a written report saying that the work needed to be done, nor did they give me an advisory note. When I asked them what the minimum thickness was for the discs, he said that they are different for different cars. I said yes but I'm interested in MY car? The BMW guy said that 23.4mm is min and mine measure 20.2. I've measured them and i recon that they start off at 23.4mm, and are now down to 20.2mm. is this a problem? Thanks