I spotted it on the back of a red camaro. It had a picture of grumpy cat and said " Would you drive any better with that phone shoved up your ass ?" It gave me a chuckle and made my day.
Honestly, people doing all that crap on their phone are putting us all at risk. There are already too many gizmos on cars themselves to keep people looking away from the road. Put your damn phones away. You don't need to be telling a fellow asshole what you are going to have for dinner when driving.
As an aside, Georgia just passed a law that it is illegal to be texting while driving. Funny how some states are all about laws to control everyone when they say they are against government intervention on their freedom (scratching head).
I like the bumper sticker says, "When you drive like I do, you better believe in God."