I picked up a screw in my rear offside tyre today so I popped on the space saver and headed to quick fit. I thought it would be repairable but apparently it had been run on flat and the inside tyre wall was nackered so I needed a new tyre. I'm running Bridgestone Potenza's and quick fit only had 1 in stock so I told him to leave it as I needed to do both rear wheels due to the quattro. I headed off to Stapletons for a 2nd opinion and they showed me the inside of the tyre wall to prove it was no good, also the rip in the tyre from where quick fit had ripped it off the rim. This meant that even if it was repairable it would have been shagged! Anyway I wangled 2 potenza's for £220 which is ok. The guy said to me that really I should be getting 4 tyres because of the quattro system doesn't like a bigger difference of 2mm between the front and rear tyres, is this true? My fronts were at 5mm so he said I'd probably be ok. The guy also mentioned that the quattro system was 40/60% ratio front/rear!!! Now I thought that these cars were prodominantly front wheel drive and the rears were hardly working until needed. This guy was convinced that the rears are doing more work than the fronts. Can anyone confirm?