Another idea:
Get a magnetic sign that advertises your business.
You can attach it to your vehicle(s) as desired.
Free advertising as you drive.
(Note: Take sign off vehicle and lock it up when arriving at your destination. Thieves like magnetic signs for some reason.)
Yep, I've got that on the truck now. I've got to get down to the sign guy and get the phone number on it changed, though.
Funny thing is, I've had signs on my truck for about eight years, and we've only gotten maybe three jobs because of them in all that time. I keep them on mostly for PR's sake. Looks good to the neighbors when I'm working on a house.
Thanks for thinking of me.