The E53 ('05 X5 3.0) is still kicking at 170k miles. I think I've rebuilt about everything but the engine block over the past 2 years, using the great info found here.

The current E60 ('09 528) is at 70k, but I just took it over, so that will go up.

The new member to the family is a 2012 MB ML350 for the wife.