Audphile

Tried to remove a rear headrest but didn't know what the aux tool was to stick in the hole of one of the collars at the base.

Turbo Freak

A tiny flatblade screwdriver should do the job. Same thing on the current A4. It is unfortunate that it needs a tool to remove them, since you cannot lower the back seat without removing them unless you measure less than 5' 8" !

miTTch

Curious, why do you need to remove?

Turbo Freak

I do not have a Q3, I only sat in one, ajusted the front seat position and then tried to lower the back seat and it hits the back of the front seat.

Only way to lower the back seat is to remove the headrest. I had the same problem with my B5 A4, but at least the headrest was easy to remove...