Hello,
According to the website How Many Left, there were 110 licensed TQS models on the road in Q4 of 2024 and 241 showing as SORN in Q4 of 2024
In my experience, I've found it easier to find listings for B5 S4s vs the TQS model, you'll find the odd one for sale here and there and if you're lucky, a few of them will pop up.
It took me a while to find one when I was looking but I got one in the end. Prices have certainly increased since I got mine. They're brilliant cars and quite underrated in my opinion.
Thanks!