I've now owned this car for a little over a year and a half. Being that I needed a highway cruiser, this car was an excellent choice. Before buying these cars, find out if some of the common problems on your model have been addressed. Namely, the radiator and fan need to be replaced at around 60k-70k miles. The waterpump and thermostat need to be replaced at that time as well and as others have mentioned, the front suspension parts don't last too long. Don't forget though, this car weighs over 4,000 lbs! Driving this car will wear down the front suspension quickly. Expect to replace it every 50k miles or so. Also, the cupholder is flimsy, therefore I bought a wedge-type holder and it's great.
The engine, excellent transmission, quick response on the gas pedal, auxilary ventilation, comfortable and quite. This car is so quiet on the highway, it's scary!
I wish BMW would have created a double sun-visor one that allows the driver to cover both in front of him and on the side. Also, a quality cupholder would've been a plus and a better navigation system would be nice as well.