What I refer to as the older style units, similar in style to what I think was the RNS-d?, are in stock and there are loads of them available but I was after the one that looks similar to the RNS-e with a large and small button both on the same side and nobody has any at the moment. There's the Pumpkin version but that's running Android 7.1 rather than 8.0 and has 2Gb rather than 4Gb.
It's probably my own fault really as I spent so much time humming and hahhing as to whether to go for a used OEM RNS-e or Android that missed out thinking the market would be flooded with them as they're Chinese. There are several brands of the same thing but Xrons certainly appear to be the most popular.
There are these which you posted a link to, which are showing as buy it now, is the Xtrons that much different or better? -
https://www.ebay.co.uk/itm/Audi-A4-...823772?hash=item285243245c:g:ChoAAOSwU-1aki35
On thing that does appear to be different is the aerial socket as it appears to have an old style, I mean really old style, aerial socket rather than an ISO or Fakra socket?