your paint. It is reflected by the d orbitals of the valence electrons in the urethane molecule and the laser is optically guided by a computer which employs a recognition camera and database to identify your car. Once identified, it knows the areas of the paint so as not to zap you in the eye or damage other parts of your car. Remember the lasers that cleaned the spray paint graffiti off of a wall in that futuristic movie with Sandra Bullock and Arnold "Come with me if you want to live" Schwarzenegger.. Case and point. =)