Does anyone know where this is located on a 545i? I think it is on passenger side. My lights are starting to act crazy and I think this is the problem.

 

its on the right hand of the car when your sitting in it, no point saying passenger or drivers side due to RHD and LHD cars.
Basicly remove the lower trim and its the black box with the big white plug, it sits behind or in front(can`t remember which) of the white car access module.