All E39s have Adjuster motors the one with Xenon HID auto adjust itself to level of the angle joint that is located at the driver's side lower arm bar front and rear. Front angle joint is about 8cm in length rear is maybe 10cm in length both the joints is connected to a device under the car the arm cost about RM120 the device about RM500.
The ones without Xenon comes with the dail.
hope this is use full..