As anyone who's ever travelled to the US of A will know, bumper stickers are something of an American institution.
For the most part, they're beloved of soccer mums, the gun lobby and Fox News viewers - so not the kind of people you'd usually expect to have a sense of humour.
But every now and then you'll come across one that suggests the driver is genuinely funny. Here are a few of our favourites...
Sod your baby on board
A fan of Primal Scream perhaps?
Say it out loud...
Taking 'horsey' to new levels
Rights for Dyslexics!
Makes a change from the standard trucker sticker
Tenacious D would be proud
An interesting existential point...
Not the friendliest of bumper stickers
Never attempt complex equations at the wheel
Slide to unlock
There can be only one
Not a regular church goer then....
One for Game of Thrones fans
Blunt and to the point
Gone to Heaven
That surely depends if you ask an evangelical or an actual Christian...
Not your average pick-up truck
Most people can read
Scary thing is, this isn't supposed to be a joke