The X5 4.6is in my opinion is simply beautiful. For the way it drives and how it does it there just isn't any comparison. I agree that maintenance is a must but your mechanically inclined and as long as you stay on it no problem. By the way these BMWs of this era can really take on the miles. I have a host of BMWs and each have been enjoyable and rewarding. My current stable includes the 635csi Euro, E39 M5, 540it and the X5 4.6is . My 540it has 178K and its a rock solid car. When I got it had the timing guide deterioration and I changed everything at the front of the engine including repairing the vanos system. I also did a complete front and rear suspension refresh that makes the car handle absolutely incredible. Everyone that has been in the car cannot believe the way it drives for the miles on the clock.