What people identify with is usually pretty complex as far as their actual identity goes. They may choose fairly weird things, but if you ask them the meaning and their own identity attached to it is usually much larger than say ... an energy drink. But that thing fits into it, so there they are with energy drink stickers all over their vehicle.

I have a sticker for a local university on my car (just one...), I didn't even go there but what it means to me is the experiences I have when I do. That's much more than a logo.