Rapper Webster Gradney Jr., better known as Webbie, was arrested this week by Tennessee Higway Patrol officers after the rental car he was driving was pulled over following a performance in Kentucky.  The 25 year-old rapper has been charged with drug possession and tampering with evidence after he threw 2 ounces of marijuana he had out the window.  The rapper also had $13,000 in cash on him, authorities said.  The driver of the rental car was charged with driving on a suspended license and another passenger was taken into custody for possessing a firearm.