I agree with Pick. ATLANTA to ALASKA or BUST..!! (Use Bold Letters...)
Secure it in a way that it will not scratch your car or come off. A good place for it would be on the Luggage Carrier, or Locker or if you're pulling a trailer, on the back of it. Note the Red, White (background) and Blue..
The words or Bust could be on a second line so the first line could be larger.
See how ya think when you're a Sign Painter..?
Have a Great and Safe Trip. If you pass thru NW Ohio, you're welcome here.