Auto-folding mirrors are nice, but my first two cars didn’t have them and I somehow managed to cope!
I don’t really have a ‘must have’ list beyond a reliable engine, a comfortable ride, a big enough boot for the wheelchair, and enough hp to get it up the hills in a reasonable time and safe for over-taking.
Extra hp and decent handling to make driving ‘fun’ is a plus, of course. A nice colour is good, but my current Golf is dark grey, so . . . I don’t need automatic windscreen-wipers, automatic headlights, cruise control (always had it – never used it), a bang-up stereo, leather seats, heated seats, electrically adjustable seats, etc.