I won't stick anything on my car. Anything that is a sticker goes in the back window for a period of time. My Dad trained me to be fussy about cars...so DH and I have to compromise. No more than two, usually around election time!
I currently just have a Minnesota Public Radio cling in the back window. I like it.
2007 Trek 5000
2009 Jamis Coda
1972 Schwinn Suburban
"I rejoice every time I see a woman ride by on a bike. It gives her a feeling of self-reliance and independence the moment she takes her seat; and away she goes, the picture of untrammelled womanhood."
Susan B. Anthony, 1896