Originally Posted by X Wife

Page 60 of my 2001 X5 manual (in the airbag section, not the child seat section) states:

"We recommend that the rear seat side airbags, if provided, be deactivated if children will travel in the rear seat. The rear seat side airbags may already have been deactivated, either at the time of manufacture or by a BMW center. Labels in the rear door opening should indicate the status of your rear seat side airbags. If you are uncertain of their status, or wish to have the airbags activated or deactivated, please contact your BMW center."

In addition, LATCH anchors are only provided for the outboard seats; you cannot use the LATCH system if you are installing a child seat in the center of the back seat. If you use that location, use the seatbelt, which is equally safe (just a bit more labor-intensive). Some car seat manufacturers allow installation on "non-standard LATCH spacing" but the vehicle itself does not.