The same exact question has crossed my mind several times. I see some pre-FL 8Ys quite frequently, but it's clearly a less common sight than the 8V at its prime. The facelifted ones I've seen only few and surprisingly many of them are rental cars in the lowest possible spec. Also tells something that the one saloon that was a showroom car in our dealer's sat there well over a year before somebody bought it out.
I guess nowadays the A3 falls in between. For the people for whom its size is enough it's a bit pricey, I think many of them might buy some more of a budget cars for their purpose. Those who got the money head straight for bigger and/or electric cars. My notion is that the Q4 is still the most sold Audi in Finland, and quite certainly some old A3 customers are interested in it.