http://coolsig.com/ is a great place to check out.
Bumper sticker suggestions for me:
My other car is a beater.
My truck is not leaking, it’s marking its territory.
No laptop – Already Stolen.
YES this is my truck. NO I won’t help you move.
You go on ahead, I’ll see you at the next light.
Don’t follow me, I’m lost too…
Cover me. I’m changing lanes.
Don’t like my driving? Then quit watching me.
Even though this is a stupid bumper sticker, you’re squinting to read it.
I drive waaay too fast to worry about cholesterol.
I see dumb people
I would give you the finger but it’s up my nose.
Driver carries no cash: He’s married!