I've noticed that the rear brakes are quite noisy when gently braking a slow speed. I had a look at the rear discs and noticed that the rear offside disk has three wear marks which can be felt when you rub your fingers across it. The opposite side (NSR) is smooth as a babies bum. Is this normal, e.g. to do with the regen function? The mileage is just over 1600 miles.