Dunno if it's been mentioned yet, but you can get convex (wide angle) glass for the aero mirrors, from Sierra Madre (and others, I think).
If you already have the Chinese repop aero mirrors that VS supplies, this glass will fit them, so you don't have to buy a whole new mirror or drill any new holes. They used to be about $60, but that has now risen to $97 (yikes). This must be due to the current 50 per cent inflation rate we're all experiencing. There's some solace in the fact that these mirrors are much nicer quality than the Chinese repops.
I've got convex glass on both sides (mine are on the fenders). On the driver's side, it made a huge difference. On the passenger side, it's still pretty worthless, but does fill in some of what's usually called the 'blind spot'.
Small mirrors like these are really meant to be mounted close to the driver (on the door). If I had to do it again, that's what I do. The farther a mirror is from your eye, the smaller the angle of view. That's why cyclists can use those tiny eyeglass mirrors to see pretty well behind them - they're mounted about an inch from the eye.