Grocery carts have loops for hanging bags with soft items.
Bagging your grocery items can be an arduous task, and soft items like bread, fruit, and vegetables can get lost in the mix and get squashed by the heavier ones. This is where the metal loops in the shopping carts can come in handy.
smarter individual would use the other hook instead of a key....
Just screw it in by hand, it isn't that difficult.
#2 not sure it would work. cars have safety glasses which prevent shattering. you can buy special purpose hammers though.
WTF? Spell much?