Bruce Willis Can't Make It Sixteen Blocks

1/18/2008 2:16 PM PST
Bruce Willis,52, made it clear that John McClane is just a character -- after David Letterman and Sly Stallone,61, were able to lose him on a short motorcycle ride through New York. Yippie-ki-yay ... where am I?

Willis was the last person back to the studio after the bit for Dave -- and he explained what went wrong while signing post-show autographs.