I just bought an 04' 4.4 X5 and I'm getting the aerodynamic kit and underride gaurd put in this week.  If you have a X5 and are looking for a body kit I suggest checking it out.  You can find it at the bmw website in the accessories page.  But let me warn you, the total for parts was $2500 which I thought wasn't all to bad but the cost of istallation is $4000!!!  I was kind of pissed when I found that out becuase I had already ordered the parts. But my SAV is going to look so damn cool when it's done that I'm going to bite the bullet and do it anyways.  [driving2]