Had one (‘05) for 3 years before my current A4. Loved it. Not sure I totally regret the sale, but I was getting concerned by the random bills and that they corrode quickly in a number of well known areas if you don’t have a garage to keep it in. I was looking around £2000 in bodywork to have it brought back to mint so decided enough was enough.
My opinion of the subframe (rear axle carrier panel)... check it... thoroughly. But if it’s not cracked and not reinforced and a post-2004 car, just keep an eye on it and be prepared to have it done. It’s not expensive. ETA do it for about £800. It costs near that much to replace the clutch. Or the discs and pads. So no biggie.
Drive both an SMG and a manual. The SMG is a lot of fun and again, not expensive to repair these days (mostly!) and the manual has a very heavy clutch and a notchy gear change when cold.
Listen for noisy Vanos, they rattle when revved up to about 3k. Some rattle is normal in the design, but a lot and you’re looking at a Vanos rebuild.
If I had a garage and a deep pocket, I’d buy a good one again for a weekend toy. Hard to find good ones and that’s why the prices are getting so high. Good luck with the search!