I haven’t.
The only bumper sticker that sticks out in my mind is that one that reads, “My kid can beat up your A student”. Used to see a lot of those.
My best friend’s bumper sticker says “WWBD?” Which stands for What Would Bacchus Do?
Not a bumper sticker but a sign in the back window of a car.
Imbush Peach.
I like this Coexist one.
(I’ve got the related “peace” sticker, which I can’t find a quick link on.)
Yesterday, coming home from work:
Vote for Chuthlu
Why go for the lesser of two evils?
I’m still looking for a “Humpty Dumpty was Pushed” sticker. We almost drove off the road from laughing so hard.
(maybe because we were stoned teenagers.)
Gorram it! I spent 20 minutes looking for that one, and only found the other 832 (estimated) “Coexist” stickers. That’s one’s my favorite, too, although I like E in the patch pictured below it best, with the “om” instead of the Venus/Mars (what’s that mean? gender equality?) symbol. For the rest of it, I prefer the blue sticker. Guess I need to make my own!
“PBS mind in a FOX news world.” Seen today.
“When I married Mr. Right, I didn’t know his first name was ‘Always’”
Found on beaters: “Honk if shit starts falling off.”
My favorite remains …
I (heart icon) love animals.
They taste great!
Coming into the 2004 election season a car in our office parking lot had one that said …
Redefeat George Bush
Honk if you love honking
On a filthy Jeep:
“Because I’m too fat to mountainbike…”
Made my husband pull over so I could take a picture.
Honk if you’re Jesus
Sucks Lysdexia! (This one was also upside down on the car)
Screw World Peace - Visualise using your turn signal!
(In small print)If you can read this, you are following too close and I am about top slam on the brakes
I is iliterite, and I vote
Please drive safely (One of us has too)
Support your local police department - Bribe Generously!
Seen on various cars in Edmonton area in last yr or so…
FML
I think I was parked next to Silenus today. the bumper sticker said
Politically incorrect
And proud of it
I saw one recently that says “Ohio is a 4-letter word”. Which pretty much sums up my feelings toward Ohio at times. 
I saw one a while ago that said: “I can go from zero to horny in 2.5 beers”
It seems not many in my area have a sense of humor.
I like “Visualize Whirrled Peas”