Duo drives Cadillac March 30, 2008 In “Iron Man 2,” the world is aware that billionaire inventor Tony Stark is the armored Super Hero Iron Man. Under pressure from the government, the press and the public to share his technology with the military, Tony is unwilling to divulge the secrets behind the Iron Man armor because he fears the information will slip into the wrong hands. With Pepper Potts and James “Rhodey” Rhodes at his side, Tony forges new alliances and confronts powerful new forces. Mos Def and Gabrielle Union are joining the cast of writer-director Darnell Martin’s ‘Cadillac Records’, Variety reports. Def will play Chuck Berry and Union portrays Geneva Wade, girlfriend (then wife) of the “Father of Chicago blues” Muddy Waters. Adrien Brody, Beyonce Knowles and Jeffrey Wright are also confirmed for the Rock ‘n’ roll pic which charts sex, violence and the civil rights movement in 1950s Chicago. The film is expected to hit cinemas 2009.