i have my "driving credentials" in there. registration and insurance info and so forth.
i used to just toss just in there, but a cop pulled me over one time and said that i shouldn't put anything else but my "papers" in there. he said it makes cops nervous when someone is rooting through junk. could be a gun. and then YOU'D be shot, whether it's a gun or not. i just looked at him with my mouth wide open.