Your car isn't public. Just like if you want to to go to the liquor store in Toronto you can not place even the unopened bottles within teaching distance of the driver. In America some states have open container laws that allows the passenger to drink his head off so long as the driver passes the roadside test.

You are allowed to own a tank, but you can't drive it on streets or place on your property (zoning laws I would imagine for the latter if anybody is part of an hoa?)

We draw the line at weapons of mass destruction. A thirty round clip in an ar14 [sic] is a lot different than a dirty bomb.