Why do people use stickers on their cars?

I guess I would say it's freedom of expression I use to have a window cling in my one van that said Peep this! and it was a picture of a chicking giving someone the bird. LOL!! I purchase it after there was a law that said we could no longer give people the bird or other signs of anger while driving. this solved my dilema and all I had to do was point at the sticker when people aggrevated me with their driving skills. LOL!!! But people do it for many reasons. I hate to put anything permanant on my car that is why I like window clings. LOL!!!

I think people might see an appealing sticker whilst out shopping and buy it. Years ago I saw a very amusing sticker on someones back wind screen. It said 'I used to be conceited but now I know that I perfect'. This really made me laugh. Recently I saw one that said 'abortion' but some letters were crossed out and the correction 'adoption' was written underneath it. So I think person that owned the first car I mentioned liked to joke around and the person that owned the second car I mentioned had a serious message in mind.