This is something I looked into when i had my 3rd gen (overseas they are equipped with power folding mirrors). No doubt it can work if you get the right mechanical parts, it WILL cost big time. Realize it's not only the power motor and other mirror internals, but also it has to be wired into a switch (OEM, non-US spec) that US spec models don't have. Sounds like a project to me!
Anyway, the switch would look similar to this: