For what it's worth, I had an '89 E30 (325i) and I put 174,000 on it before I sold it this summer. I kept the car maintained well and I never had a serious problem. Auto transmission was still crisp and tight; the engine still pulled strongly until the rev limiter woke me up and I never had the head, intake, or oil pan off the car - never needed to.
There is a big difference between driving a BMW hard and abusing a car. Drive it as hard as you want and if you keep it maintained, it will serve you well long after the warranty is only a memory. If you abuse a BMW for any length of time, you better have deep pockets.
Enjoy the ride.
