Hi there Can anyone shed some light on what the plastic box is above the rear wheel arch (passenger side, behind the cover in the boot). Basically the rear brake light (passenger side) went on Saturday, but can't pull the plastic housing out as it interferes with the said plastic box. I was able to unclip the housing and angle it enough to get my fingers in, to remove the bottom bulb, after replacing it, it still doesn't work, so need to know what the box is before I remove it so I can clean the contacts etc... I've not checked the fuses as the other brake light works! (I will check it though) A3 Quattro TDi - facelift (51 plate) Anyone replaced this bulb and find that it still doesn't work? Is there a know wiring problem? Thanks very much.