I have a 2000 Audi a4 Quattro turbo the brake light are not working because i have a bulb out on the passenger side but the hole in the tail light is square dose that side take a special bulb...all the bulbs are round...

 

That's not a brake light slot.

 

what is it for

 

rear fog light...

 

you mean the rear fog light is in the tail light...and what kind of bulb is it

 

im sure youve noticed the 2 fog light buttons on the center console. the second one is the rear. i dont know what kind of bulb it is just because i never put one in. from what ive heard you have to carve out a bigger hole to make it fit.