Hmm, I dunno. I did look at early MX5 mirrors, they bolt straight to the body but the issue that I want to get away from is the adjusting of the whole unit rather than the glass.
Every time I walk up my road I compare the profile of newer MX5s parked on there, Fiat 500s and a Matiz, and it seems to be the best bet...
The 500 mirrors, along with the new Mini ones just look huge and IMO would look cumbersome on a beetle. Mazda ones are nice, but they need some fab to make them look nicely, think someone did a thread on here not so long ago...
These are the matiz ones I'm looking at