“This is the first year since I have been tracking that 100% of vehicle thefts occurred in unlocked vehicles. Not a single car window was broken to steal anything.”

I learned my lesson about this when I was 17 in Chicargo.  It only took one occurrence for me to get the message. One response to Greg’s post on Facebook was:

In that 3 month period my next door neighbor had his UNLOCKED car broken into IIRC 4 times.

Locking your doors is part of what’s called Defense in Depth. Sure, some criminals could still get in but the harder you make it, the more of them will just go somewhere else.

And please don’t leave firearms in your car, either, even if it’s locked. Your car is not a holster, as Pat Rogers put it. If you sometimes have to go into places where you aren’t allowed to have your firearm on your person, get a lockbox or safe for your vehicle. The ‘truck gun’ concept is a load of Horse Hockey.

http://www.activeresponsetraining.net/lock-your-damn-doors-2018-edition