looking at replacing the whole front end with new parts as im getting some knocking and now the car is 14 yrs old thought i would treat it to some shiney new bits.
the car is a 99 a4 2.4 suto avant, but i am unsure what size the lower ball joint is and it appears to be two sizes a 16mm and 20mm and im not in a postion to take the car apart as of yet to find out what size mine is.
could someone shed any light on thi before i oredr the parts?

thanks bubba

 

This is for US A4's so I don't know if yours is the same but I would guess so: Control arm track control arm suspension wheel bearing housing wheel bearing housing wheel hub suspension stabilizer front. Fits: 1999 Audi A4 Quattro Avant 2.8L | Jim Ellis Audi Parts

It says both lower nuts are M12.

 

I'm guessing the difference is between the A4 and S4, in which case I would assume it to be the smaller one.