I like the, "We don't need no stinking roads".
Gray T-Shirt, red lettering, over a print of an ATV tire tread.
When I had my dirt/trails bike I painted the front tire and drove it over a gray sweat shirt. I printed O-H S-H-I and the last letter was covered up by the tire marks. The praise was used by me alot, as I seemed to get into stuff I shouldn't. Like going over a hill, not knowing the other side was a river bottom with nothing but mud. Took 5 of us to get my bike out and back up the hill.
Or simply run a tire tread diagonally over the back and in the upper left corner write, "DO IT TO IT!"
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2006 Slate Blue Metallic H3, FlowMaster exhaust, True Flow cold air intake system, Ground Force rear lowering kit, custom locking fuel door, chrome hood grill w/handle, US Speedo gauge kit (chrome and red numbers), Custom rear tire cover, chrome tail light guard, custom paint on skid plate, new pin stripping, USMC front license plate.
Semper Fi