I've got California copies on my car and so far they've been the best I've found. I've had Sebring style, mounted almost directly on the door and the driver's side was ok, the passenger side, as BDA says, just there as an ornament. I've also tried the stainless "bullet" style on a pedestal which does allow a lot of movement with the mirror, especially if you modify the internals. They were ok in terms of view angle but they are small mirrors compared to the California ones.
Basically you need a mirror on a pedestal to get the angle of view across the cabin and the longer the pedestal the better angle you get. The downside is vibration and movement, I've locked mine in place to stop them drooping on our lousy, bumpy roads. To get the angle I spent a bit of time with duck tape holding them in various places, markers behind the car and just trying it. Although they look approximately the same there's a difference in the mounting plate and pedestal angles on either side.
A convex mirror is better but due to the viewing angle from inside the near side is never going to be as good as a modern car and it's (generally) larger mirrors.
I think some of the modern motorcycle or racing car mirrors would work but I'm not so keen on the looks on an old car. Quite honestly I only ever use the nearside when I'm reversing in or out of the garage, I never bother trying to use it when driving on roads.
Brian
