Great DIY! For anyone that's looking for the cabin recirculation filter HERE is a link to the part.

ECS Tuning

Great DIY. I did this yesterday. Mine was worse than your dryer screen after ten loads of laundry!

I note that the part on the ECS site says it is for "four zone climate control only."

Does this mean if you do not have the optional four zone(rear) system you do not have this filter?

I'd hate to take things apart, only to find my model/option does not have a filter in that place.

That filter is for cars with X5s with the 4 zone OR automatic climate control. The update just hasn't hit the site yet.

Thanks for the instructions Tony. Very helpful.

I also wanted to change the air cabin filters in the engine bay compartment. BMW says there are two, they even gave me a pair in a box at the parts dept. I found the one on the passenger side, but I can't find the second one. Anyone know where it is?? The driver side has nothing. Any help or info would help. Thanks.

If I recall correctly, they are both on the passenger side at right angles to each other. I believe you have to remove one more piece of plastic housing once you remove the first of the two filters to get to the second one.

Thanks again Tony.
Funny story, 'cause last time when I changed the first one, I didn't unplug the cover completely to look in there. So this time I unplug the cover and put it aside. I started looking in there to see if I could find the second one. My cousin comes around is asking me why is one of the filters old and the other is new? I look at the cover now upside down and I see the second filter, placed right next to the first one, on the same cover. I was laughing, and embarrassed at the same time, since it was right there. Problem is, the graphics (on RealOEM.com * BMW E70 X5 3.0si Microfilter/housing parts) provided by BMW don't show two filters side by side. They just show one.

Here's a picture of it:
Imageshack - img20120701191012.jpg

could swapping out these filters affect how much air i feel coming out of my vents? The side vents for driver and passenger push out so much less air then my center two, is this normal? thanks all.

If the filter is heavily heavily clogged replacing it could increase your air flow.

Thanks Mate!! My independent mechanic did not know where the cabin filter was, so I came home, read your post and VOILA!