Auto-Leveling is the new feature that was introduced in the late 90. Auto-Leveling is a feature that incorporates a motor/servo built in a headlight which operates/actuates the headlight's inner adjustment mounts, which moves the Beam output angle up and down (either by car's ECU/OBC automatically or via a Self-Leveling Switch inside the car cabin). This headlight feature is to provide the best lighting angle for the headlight beam output, which helps maximizes the driver's visibility while also doubling to help not blind the oncoming traffic.
The earlier generation of Auto-Leveling headlight (1995-2002) would have the auto-leveling feature with itself having a separate connector for BMWs. While Audi / VW would feature removable Auto-Leveling motor which can be removed from the stock headlight to be put on the new headlight if it has the capability to accept the stock auto-leveling motor, then the user will continue to enjoy such feature. While the later generation of Auto-Leveling, everything is now narrowed to a single big connector that has many metal pins inside for all features including low beam, high beam, parking light, auto-leveling even signal light…etc
This headlight feature was originally offered/introduced exclusively for the top of line models. However, the headlight feature quickly became a government standard for Factory Xenon models because of the HID Xenon being much brighter than Halogen light. However, Euro-spec vehicles might often have the Auto-Leveling feature available for Factory Halogen headlights.
Easiest way to know if your car has Auto-Leveling or not, is simply to turn on the headlight, if you see the headlight going up and down for a few seconds just after car’s ignition, which means you have Auto-Leveling.
If you originally don't have an Auto-Leveling headlight, upgrading to a headlight that comes with Auto-Leveling motor and feature will NOT make your car to have Auto-Leveling, because Auto-Leveling has to do with more than just the headlight upgrade. It also has to do with re-programming of car's ECU (which only dealer have the machine to perform) plus some extra wiring harness and adapters for the Auto-Leveling plug.
*If you originally don't have an Auto-Leveling feature, upgrading to a headlight set that features an Auto-Leveling motor and/or feature does not mean that your vehicle will be able to utilize it. If you originally did not have this feature and would like to activate it, you may need to re-program the car's ECU (which Dealership should only perform) . You may also need some extra wiring harness and adapters for the Auto-Leveling plug/motor. Most of the Mercedes, Audi and Volkswagen's Auto-Leveling plug are incorporated within the main headlight connector. Whereas much of BMW headlights (mostly E38, E39, E46, E53 Chassis) have the Auto-Leveling Plug separate from the Factory Connectors. For the listed BMW Chassis above, the auto-leveling plug should be accessible/seen behind the headlight assembly.