Bumper stickers and car magnets are an interesting window into human identities and human values. Generally people aren’t paid to put these kinds of things on their vehicles so we know they’re authentic. And in our culture, a car or truck is a serious reflection of who we are. We’re generally very careful about what kind of vehicle we own, much like we’re very careful about what kind of clothes we put on to be seen in. Given these factors, bumper stickers are powerful indicators of a vehicle owner’s values. From rainbows to Darwin fishes, there’s a surprising amount of background knowledge needed to really get the iconography. And sometimes it’s just really straightforward.