I was able to add rear fog lights to my US Spec 2006 325i simply by adding the euro spec headlight switch (with the rear foglight switch) It uses the lights for the adaptive rear brake lights when switched on. So there is no adaptive function when rear foglights are on. That was all I had to do. I wonder if the x3 with adaptive brakelights is similar? Does anybody know? maybe we won't need an LCM. Does the e90 have an LCM? Forgive me if I sound naive, but electrical engineering is not my thing.