You could cut a back plastic piece and have it velcroed to the faceplate. Strategically place the velcro around the outer perimeter so it does not interfere with the viewing area glass.
You could also have poisoned darts discharge when someone breaks your windows, but that may result in consequences.

I thought about doing the plastic thing, thats probably the best bet without getting out of control.  I do wish the xb had the cover like the tc has, you would think with Scion offering factory nav systems they would carry over that idea.  I hate being on the other side of the country, not knowing what kind of automotive predators are lurking around my new baby.