Personal cars for business use. Thoughts on bumper stickers?

I saw a car that was quite obviously a personal vehicle being driven for business use the other day. The name of the company was clearly displayed on the vehicle. The car had a bumper sticker that said, “Do all jobs suck, or just mine?” Not the best advertisement for the company, to be sure!

I don’t think businesses should have a right to tell you what to put on your own car, but I do find it inappropriate and wonder if it could violate some clause of representation of the company in some instances. If you accept a job with the understanding that your car is to be used for business purposes and you are reimbursed for expenses incurred, your vehicle should represent the company appropriately.

What do you think?