Ah so aluminium uprights with the steel inserts for the balljoint tapers.
Unfortunately its a common mistake where the insert comes out with the arm which then goes in the bin. Its not available as a separate part so you have to kill a good upright just to get the insert, and as you have found, those uprights are becoming extremely scarce now.
The A6 and A4 use a similar system, but I've never actually checked if the inserts are the same or compatible. I will have a look tomorrow
