I've had a mess of problems with my 01 but BMW has fixed everything (even after the warranty expired).
Biggest problem is the crank case ventilation system. Replaced 3 times so far. Last time it failed, it blew oil all over the engine compartment. Dealer now recommend 0-40 oil in the winter.
Lower control arms replaced twice. Exhaust valve and related components. Rear hatch latches will fail again.
But... 4 years old with 73k... and rides like new. A blast to drive. No plans to sell.