I'm pretty impressed with the abuse my factory power mirrors have taken. I was a little worried when I bought the Jeep but so far so good.
I did just install some amber KC Cyclones for turn signals. Holy shit they are bright! They light up the whole lane next to me. Might be possible to mount them on the mirrors if you are into that kind of thing.
This pic is with bright lights on in the garage...
Those are nice but I'd be afraid of breaking one and being out 90 bucks.
For under 7 bucks a mirror, I could see my cheap ass popping these in the outside wall of the plastic housing:
EDIT: I could see me doing that ^^^ if I wanted turn signals in my mirrors . . . I don't see me doing shit. http://www.amazon.com/Maxxima-M09300...dp/B002NS8Z2C/
They're pretty bright. I have 'em as the front turn signals on my DR650 "wanna-be dirt bike":