What, actually, would be the point of this even if we thought Officer Friendly was doing us a service? And aside from a phone or a gps navigation system, which aren't exactly worth big bucks, what "valuables" are people going to be leaving in their cars that wouldn't require a full search? Maybe people leave some cash in a bag or something, but figuring that out would require a pretty deep search.
Back in the dark ages car stereo systems were worth enough that people would steal them, but I doubt even the fine officers of New Haven planned on ripping them out just to make a point. Or maybe they did.