Originally Posted by suprafrank
Hope this will be helpful for someone who wonder what is one of the ways to correct the sensor arms position by yourself in your garage and without taking the wheel off the car.
I had the same problem with the headlight aiming very high after installing Eibach pro springs. I checked the front sensor that seems to be hooked up properly. I didn't know there's a sensor in the rear also. after reading this post, I checked the rear sensor and "BAM" it's hooked up incorrectly. I was trying to figure it out how I can correct it myself without going back to the shop where they installed my springs.
The easiest way to do so is to lift up the driver side rear wheel with a jack (I used my other car's jack as the e92 M3 doesn't come with one (I can't find it). Then I thought I need to remove the wheel in order to get to it. BUT then after I lifted the car with the car jack, I noticed that the rear end is high enough for me to stick my head under it and my hand can reach the sensor that way. By the way, that sensor is next to the spring (inner side of the spring so it's a bit more difficult to get to it by passing my hand/arm under the wheelwell even after I remove the wheel--I think). So anyway, after making sure the jack has securely lifted up my car, I laid down on my back and stick my head under the car and try to remove the screw that connect the 2 plastic arms together. That wasn't successful as there seems to be a ball joint at the end of that screw and that just keep turning thus the nut wasn't going anywhere at all. So I used a mirror to help me to look at the sensor unit that attach to the upper arm and the car body and "BAM", I figured out what to do. There's 1 screw that fix the senor unit to the car body, all I had to do was to take out that screw (there's a small metal part stick out from the sensor unit which goes into a hole on the car body/part that helps to align/fix the unit at only 1 position so when you put that screw back on it will be fool proof to have the unit installed back to the correct position. Just make sure that metal part stick back to that hole before you put that screw back in). So I unscrew the screw and rotate the arms carefully so now the upper plastic arm (which is attached to the sensor unit) is lying horizontally instead of vertically down. There's enough room to do that and I didn't have to disconnect the wire/harness to that sensor unit.
That's it. Not too difficult to do. You just need to have the gut to stick your head under the car to do that. No need to remove the wheel and put it back on. Just make sure you put something on the floor to lay your back on so you will be more comfortable. For me, I used my kid's pack-and-play pad.
I think the auto level is working now but unfortunately since I had manually adjusted the level before now I have to readjust it (I think). I will do that tonight.
Going to give this a shot tonight. I'm glad I did a SEARCH before posting the same question and all you guys ripping my head off for not searching.