An externally thrashed stainless Ruger revolver, with internals in good condition, would be my choice. (I own a couple of candidates; Security Six and GP100, acquired cheaply.) It would NOT be kept inside a large bag with other stuff, but individually secured, in such a way that a car burglar would have to do much more than smash a window and engage a remote trunk release or fold the rear seat forward!
Actually, carrying that strategy a little further, my get-home bag is empty! It is stored flat, and my get-home items can be inserted as necessary. In my area, car burglars mostly want laptops, computer tablets, GPS systems, smart phones, and such. (Of course, they will not ignore guns!) A bag or case is a target, because it can be stolen in seconds, serves as a convenient tote system, and can be sorted-through at leisure in a safe location. A high-quality backpack can be a target, itself, as burglars love to use backpacks to haul their loot. The car burglar usually does NOT bother to look into a bag before stealing it, therefore, I try to make a bag appear unrecognizable as a target.
I do not presently keep a firearm inside a vehicle on a daily basis, as my LE status enables me to carry on my person almost everywhere. I also have safe, secure storage at work for spare weapons.
Actually, carrying that strategy a little further, my get-home bag is empty! It is stored flat, and my get-home items can be inserted as necessary. In my area, car burglars mostly want laptops, computer tablets, GPS systems, smart phones, and such. (Of course, they will not ignore guns!) A bag or case is a target, because it can be stolen in seconds, serves as a convenient tote system, and can be sorted-through at leisure in a safe location. A high-quality backpack can be a target, itself, as burglars love to use backpacks to haul their loot. The car burglar usually does NOT bother to look into a bag before stealing it, therefore, I try to make a bag appear unrecognizable as a target.
I do not presently keep a firearm inside a vehicle on a daily basis, as my LE status enables me to carry on my person almost everywhere. I also have safe, secure storage at work for spare weapons.