The factory mirrors on the WR250R are not only ugly, but they probably wouldn't fair too well in a crash. I decided to try some clamp-on mirrors on my WR250R, which simply clamp onto the handlebars near the cross brace. They take some getting used to since you have to look down at the mirrors, but once you get them adjusted, they seem to work pretty well. Since they are tucked down low and out of the way, maybe that will protect them in the event of a crash. Here is a closeup view.
Where To Buy:
WR250R Clamp-On Mirrors at SoloRacer.com