Tony faces his toughest challenge yet in the second full trailer for Marvel's "Iron Man 3," hitting theaters and IMAX 3D May 3!Subscribe to Marvel: http://bit.ly/WeO3YJStay up-to-date on "Iron Man 3" on:FACEBOOK: http://www.facebook.com/IronManTWITTER: https://twitter.com/Iron_ManKeep up with Marvel on:TWITTER: https://twitter.com/marvelFACEBOOK: http://www.facebook.com/MarvelTUMBLR: http://marvelentertainment.tumblr.com/GOOGLE+: https://plus.google.com/+marvel/PINTEREST: http://pinterest.com/marvelofficial/