I had a similar experience to Ian - my external mirrors are these:
They passed the IVA - but were marginal for size, and ability to focus on the zone required in IVA.
In use they are very small compared to what we are now used to on modern cars, and dare I say I feel are dangerous due to the very limited area of vision they provide. I would like much bigger ones from a safety perspective.... but what modern mirrors would look right?
I used a modern Ford Fiesta rear view mirror - totally IVA friendly, easy to stick on the screen with a double sided pad, a good size for continued use, and cheap to buy. It has remained on my Cabrio and works well.