Bearded ATV
Select Extras from the main menu and then choose the Extra Content option, at which point you can enter a code. If you enter BEARDONWHEELS, you are supposed to get the "Bearded ATV," though there have been reports that the code doesn't work for some people.
Redneck Logic Uncle Si Trivia Game
From the main menu, choose "Extras", then "Extra Content". When prompted, enter the code: REDNECKLOGIC.