I too saw something similiar on Ebay. They stick on the outside of the mirror and would obstruct your vision when using the side mirrors. I think that was a great idea to put it on the mirror housing.
Best wait 'til someone makes a kit where the LEDs are behind the mirror like most factory vehicles equipped with these.. aka expedition, etc.
This mod is a great idea, atleast the person in your blind spot will know they are going to get ran over and can move the hell out of the way.
