bumper sticker agenda

i don't understand bumper stickers. they make no sense to me. i understand people want to share their opinions with their fellow drivers, you know, who they are voting for, some thing they believe in, people they don't like; but honestly, unless it is mother theresa behind that wheel with a Jesus fish on the back of her car i think the views pasted to someones vehicle can hinder who they are trying to support.
for example, if a person is driving their car on the freeway with a peace-promoting sticker let's say it says "visualize world peace," nice and simple right? but you accidentally cut them off on the freeway and they drive by you like a mad person with a certain finger and explatives. does this person really support peace? i would question what type of peace this person was trying to visualize.
also, what if someone who supported al gore back in the 2000 election and had the bumper sticker "gore/liberman 2000" and then you saw them littering? mr. gore would not approve of this for he wrote some books on the enviroment and has been a big activist for it. but someone who didn't know mr. gore's environmental background may think, maybe this candidate is ok with someone who supports them littering?
my last example really bugs me and there are many combinations both in the right and left. there will be a Jesus fish on the car right next to a bumper sticker that says "the road to hell is paved with (fill in the blank, republicans or democrats)." i'm sorry, how did that person get to decide who goes to hell based on political preference? not to forget though that Jesus preaches love and that we should not judge. so from a non-christian perspective, i would want to run far away from christianity if that's how they look at the world. i don't want to be judged and i don't want your car to tell me that you would judge me.
so i guess in the end, bumper stickers are baffling to my mind.
if you have stickers on your car, that is ok, i don't want this to sound like i hate you or anything. but, what i am saying is that bumper stickers can help and hinder the people or causes they represent and sometimes i just don't understand them...