Re: How do I adhere a rear-view mirror to a Plexiglass windshield?
I'd suggest a temporary application first, as you may find that you don't want one all the time, in the way, or that a car-type rear view is useless on a boat. Then start drilling and mounting.
The best one I had was a clip-on convex, about 2" by 1" designed to clip on a car visor, to see the babies in the back seat. Iclipped it on to the windshield frame only when towing.
As for age of the topic, this one is useful for many boaters, unlike the useless when old posts like "should I buy this boat?" or "How often do you use your boat?" posts.