2001 A4 taillights??
 

I just got my 2001 A4 and discovered a taillight out. There was no bulb in the top socket on the passenger side because the hole that the bulb goes through was flat on top and bottom so the same bulb that is on the top of the driver's side won't fit. Does anybody understand what I'm saying? The top sockets are not the same. ????

I don't completely understand what you're saying but I think I do know what you're saying. You might be talking about the top part of the tail lights, in which it is made for "rear foglight". Noticed I said foglight not foglights since Audi purposely only made one rear fog. You could modify the other one and make the hole larger if you want.

thats what i did hahah. i files the hole and made it bigger, and you took the tail light relay out of jetta and just took the little metal thing needed to have power go to the bulb and presto, i now have two =D

So is there not supposed to be a bulb in the driver's side top position?

yes. exactly.

The reason being that to any non Audi owner, two rear fog lights might look very similar to brake lights...

which it does and makes it a very annoying mod. Only good mod imo for that is to make top and bottom brake lights and just get rid of the rear fog.

The bulb in the top of the drivers side is the "rear foglight" which all it really is is a bright taillight on a separate switch. The missing bulb on the top left was so Audi could use the same tails for both right hand and left hand drive models of the car. They would just file out the passenger side and put the bulb in that side. Both light bulb sockets work and if you file the passenger side out so a bulb will fit then when you turn on the rear foglight switch, it will look like bright tail lights in the top of the tails. I use this for when people are tailgating me, i turn them on and they think you are braking, so they instinctively hit their brakes. making them back off.

Oh and ya they also come in handy in the fog so people can see you from behind lol. But who ever uses these things for what they were meant for???
-Tyler

Haha I never considered this before. I might just have a reason to do this after all!

This was the first mod I did to mine. Looks great.