Shaq -- Go-Karting Into Retirement

6/6/2011 12:55 AM PDTby TMZ Staff Shaq got a head start on his retirement -- the 7'1" NBA legend wedged himself into a tiny go-kart in Tennessee recently ... and sped around a BADASS race track with his girlfriend Hoopz.It's just like that episode of "The Simpsons" where Nelson laughs at the tall guy in the tiny car -- not that we think Shaq looks ridiculous or anything ...