You don't get a tyre pressure warning if its a slow puncture.
Before I got the M I had a 3.0si with runflats. Un-known to me I drove a 40 mile round trip 5 days a week with a completely flat rear tyre!! don't know why I didn't notice but the only difference was the traction control was kicking in more often..lol
Scary to think I drove on that tyre for 3 months. Thing is BMW took the tyre off and said it looked ok apart from the puncture. Obviously I got a new one and started to check my pressures more often.
