hi im new to your forum looking for some advice my young cousin has went away and bought an audi a4 estate but it has issues. for starters the windows dont go down the central locking does nt work when you press the brake the sidelights come on although i think that may have stopped also cant get the boot open ive checked for water in the footwell theres none i do think this maybe the problem i noticed a yellow wire that looked out of place in the back arch its actually a live feed coming from the 12v power supply in the boot wired to some sort of control box but dont know why ill include a couple of pictures thanks in advance for any help i recieve.

Does the car have a tow bar perhaps? That could be control box for the wiring of one.

As for the problems with the car I would be looking at all fuses and relays to see that they are all working. Might also be worth having the car read for faults but by VCDS rather than a generic fault code reader.

Best of luck.