The attractive pricing on these cars has made me start looking around, but before I get too serious I want to know more about them. Are they any less reliable over the standard x5s?

I read somewhere that they have air suspension, is this just self leveling or does the car actually raise and lower as well? What are some major maintenance items that pop up at 75k miles and 100k?

What should I be on the lookout for when I go to check out a car?