As much as I love that sticker and message, I would never put it on a work vehicle for fear I might offend a customer.
Bingo! Especially when you're picking up or delivering automotive freight, where the smarmy union members just luuuuuv Obama.
Every 4 years there are a handful of small businesses that put signs out front lauding their favorite candidate. It may make one feel better to do that, but they are in effect instantly alienating half their customer base.
One clear example of a sticker-like instance was an excellent photographer that I worked with at Olan Mills in the Church Directory Division. He had a license plate frame that read, "Jesus is coming. Look busy."
OK, that's hilarious, but to most Christians, by and large, Christian Humor is an oxymoron. It wasn't long before a few churches specifically requested that that particular photographer not come back for future photography sessions. He was told to remove the frame, and objected citing his Constitutional right to free speech. Management agreed that he had that right, but also noted the Constitution did not guarantee him the right to keep his job if he continued to offend their customers. He removed the frame.