Watch Your Car is a national vehicle theft prevention program funded by the United States Department of Justice, Office of Justice Programs and the Bureau of Justice Assistance. It is a voluntary vehicle registration program designed to deter auto theft and assist in the apprehension of auto thieves. Participating vehicle owners sign an agreement stating their vehicle is not normally used between the hours of 1 am and 5 am.
Vehicle owners receive decals that they apply to their windshields. If a police officer observes the vehicle being driven anywhere in the United States during these hours, they may stop the vehicle and verify the vehicle owner or a person designated by the owner is operating it, and that the vehicle is not stolen.
Given that the 3rd District seems to be leading in car thefts, this is definitely a good idea. Unfortunately, it doesn't help with the even bigger Theft From Auto problem.