5M0-907-357C, this is about $166 from online dealers. This module is mounted inside the cabin, behind the glove compartment, and reads the signal from the level sensor, which is attached to the rear suspension. The AFS control module reads the average front-to-back level of the car, and sends this info on the CAN bus to the Headlamp Power Output Stage Modules, which then controls the leveling motor inside the headlight housing. This is used with earlier set-ups (front and back level sensors).
$100 includes shipping. I have two of these for sale. (You need only one for your retrofit) PM me.
Last edited by CC'ed; 12-05-2012 at 09:03 AM.