I have a 2001 M3 Convertible and need advice. First, I get a strange noise that seems to come from the tyres, it's like the noise from a flat tyre but is only heard on each complete wheel rotation. I have tried different tyre pressures and the front are inflated to 2.2 bar as BMW recommend on Pirelli P zero's 225/35 Z18. I have had the tyres checked by a tyre company and they tell me that they are fine. Second, the rear tyres are Pirelli P zero but 255/35 Z18 and are inflated to 3.3 bar as BMW recommend. The problem here is that when I turn a corner they sound as though they catch on the wheel arch. If I lower the pressure to 2.6 bar (ish) then they do not catch but the tyre pressure sensor will not go out. It is driving me mad, can anyone please assist?