Traditionally, you use the glove box for storing your car's manual and perhaps a box of tissues. But redditor revmonkey1977 suggests you ought to add greeting cards as well. That way, you always have one handy if you need to bring one to an event.
I figured this out a few years ago when my magical powers of procrastination prevented me from taking an assortment of Thank you, Birthday, Holiday, Sympathy cards out of my car. A couple months later, I was out with a friend and we got a call to come to a birthday party. Pulled out card, wrote hasty message and put in envelope. Suddenly I'm a really considerate guy with no real time commitment at all. The same thing happened three more times in quick succession.
Not a bad way to seem thoughtful without making much of an effort.
Keep Greeting Cards in your glovebox [Reddit]