Purchased new. Always followed recommended maintenance schedule. 54,000 miles driven as of jul/2010. Front brakes replaced under warranty (28,638). Starting to have lots of maintenance issues. Heat exchanger (34,113 miles). Thermostat (37,803). Front axle boot (47,488). Brakes fluid needed flushing (52,779). Rear brake light assembly (53,353). Front thrust rod bushings replaced (53,793). Told we need to replace other front axle boot. Passenger side a/c not working. What is next? All BMW repairs are not cheap. We purchased a 2005 Ford escape SUV (now with 57,000 miles) and have experienced only brake replacement. We didn't expect a $50k BMW to have these issues. We intended 2004 x5 to be 100,000 car.
Drives and looks great (outside and inside).
BMW should look at their quality control and engineering at the South Carolina plant. We've owned 4 BMW sedans and didn't have maintenance issues as with the X5 SUV.