I'd think you have to have the base unit / computer for the LED's to work. Interested in hearing the ease of install though - it looks like a bird got in a fight with its reflection in my drivers side mirror.

 

If you don't already have turnsignals in your mirror glass there will be some wiring necc to install. It would be poss. to tap into the turnsignal wires in the harness to accomplish this. As far as the defrost setting you must first have a rear window defroster if you don't I'm not sure how to set that up. The add does state they are a replacement glass and I would say there not intended for upgrade, but it wouldn't be hard to make signals work.