The easiest way to tell if you have self leveling is to watch the lights when you first turn them on. If they dip up and down quickly when you first turn them on them you have self leveling. To verify, just look under the bonnet at the back of the headlamp unit. In between the high and dipped beam housings should be a black box with a cable coming out the back - this is the self leveling unit which houses the servos.

How can I know if my X5 4.4i has self-leveling system on the halogen headlamps? Thanks!

Look at the back of the headlamps, if you have the small black box with a cable coming out of it as below you have self leveling.
http://xoutpost.com/gallery/files/2/7...f_leveling.jpg

If yours looks like the below, then you don't !

http://xoutpost.com/gallery/files/2/7...nselflevel.jpg

So let me get this straight: If you want to remove your current headlamp assembly and replace it with a xenon assembly, your current headlamps need to be self adjusting or you can not do the replacement?

'03 4.4i

Legally correct. Actually you can and it is as easy to do as the articles in xoutpost.com show. US spec. vehicles only have the self leveling fitted in the xenon light clusters. (As you are in Houston I would think that you have a US spec. vehicle.) Don't worry about that aspect. There must be thousands who have done this mod.
If you need more info PM me.

Cool. Thanks in advance :thumbup: I am probably going to buy some stock xenon headlamps with ballast and projectors here in Houston; got a company selling both sides for 400+. I just didn't want to get them, plus 200 on the angels eyes, bake'em, install'em (AE's), re-bake'em, and mount those on my truck and they didn't work. Plus, i've never built a relay before; any suggestions on a pre-built set or is it just that easy???