On my '01 X5 3.0 I had the all 4 pads replaced 3 times and had a full set of rotors done twice--that was done up to 100K mile mark before it got totaled in an accident. It was $1,400 at my indy shop for all 4 pads/rotors on the '01 and the 4.8 20"s wheels have more expensive brakes I would bet. And all 4 pads on my '08 were replaced at 15K miles (I have 19K now). So, between all of that, the oil changes, belts, spark plugs (at 100K miles), brake flush every 2 years--it all adds up + you don't have any expense surprises on the brakes. You just drop the keys off, get in your 335 loaner and you are done. That's why I got the extended maintenance. My $.02.