Apparently you people have never had a car looted.Grab a brick,bust the window and clean it out.Takes 15 seconds and they are gone,think about it.
You are exactly right - breaking a window, grabbing whatever is handy and then departing the AO is exactly how the average thief works.
This is exactly why, if I have to leave my concealed carry firearm in the car, I leave it in a lock box that is either bolted under the passenger seat (my car) or cabled to the seat frame and placed out of sight under the passenger seat (spouse's car, rental car, etc).
One thing to consider however is that a break in usually starts with targeting a vehicle that has something of value visible in it. Whether it's a cell phone, purse, wallet, GPS, cash, credit card, etc, it's usually the sight of something of value in the car that prompts the person to target that vehicle. Sometimes it's secondary evidence of something valuable, like the faint ring left on the windshield by the suction cup of a GPS - that might be enough to prompt the thief to break the window to check in the center console or glove box.
If the inside of your car looks as clean inside as the a rental car you just picked up from Hertz, there's not much reason for a break in - a potential thief will pick a car with a more obvious return for his investment. If you have valuables in the car, make sure they are out of sight, along with any lock boxes, cables, etc.
Where you park matters. A locked garage adds another level of protection, a well lit parking space or a parking garage with video monitoring are also deterrents. Parking in a dark location in a bad neighborhood when you can't continuously observe your car is a really bad idea.
In the event someone does break in, they are not going to spend a great deal of time trying to remove hard to find and hard to remove items, so step two is to ensure any valuables in the car are also secured inside the car. A lock box bolted to the floor under a seat or secured with a heavy cable takes time to remove that the thief probably doesn't have or doesn't want to take.
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The point here is that yes, people should take some basic common sense measures to prevent guns from finding their way into the hands of criminals and prohibited individuals - but there is also a reasonableness standard that applies.
Expecting people to leave their concealed carry or self defense firearms at home just because they might get stolen from a car, is counter productive, as a gun left locked in your gun safe at home is worth absolutely nothing in a self defense situation when you are some where else. You'll never need a self defense handgun, until you need it real bad, and then, much like a parachute, if you don't have it when you need it, you'll likely never need anything ever again.
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As for law enforcement officers and keeping firearms in cars, the same common sense and reasonableness standards apply, plus a couple additional measures.
Police officers often carry weapons off duty in their cars. Unfortunately, those cars are often unmarked police cars - that look like unmarked police cars. It's also lost as bad when they have police association stickers, special license plates, portable emergency vehicle lights, etc, that scream "off duty police officer's car - weapon inside". You need to avoid that.
Police officers also often carry go bags with weapons in them in their off duty vehicles. At a minimum the bag needs to be completely out of sight, and ideally the weapon would be locked in a lock box or in a secure weapon rack out of sight.
Inside a patrol vehicle the officer's secondary firearm(s) should be readily accessible from the front seat, but they also need to be securely secured in a locking rack. Whether it is combination, keyed or electronic doesn't matter, just as long as it's locked.
