Has anyone else's S3 done this before? Put £20 of V-Power in, went up to 1/4 - drove 10 miles and the gauge went up to 1/2? I've had it before where the gauge was on 1/4 then suddenly dropped to R with 10 miles range on the display (and ran out of petrol on the way to work with 10 miles left....... less said about that the better) Driving me mad, I'm just guessing now as to how much fuel my car has in. Any ideas where I should be looking if this is a fault? Hopefully a cheap fix as car failed MOT today :-( Thanks!