To escape from being buried alive, Michael and K.I.T.T. use April's Trajectory Guide feature, described here as being "new." However, the system was previously used in the episode BLIND SPOT at the beginning of the season. The reason? Despite being the last episode screened during the second year, Big Iron was one of the first to be produced; in this case, the bad continuity was due to the episode being held back in the running schedule.
April appeared in early versions of the script, explaining to Michael about the new Trajectory Guide and Ultraphonic Analyzer. Michael's hatred for April's new addition to K.I.T.T. doesn't surface in the episode, and most of his banter with K.I.T.T. about it is also cut. April does not appear in the episode.
As a result of it's delayed slot in US schedules, this episode was screened first in the UK on Thursday, February 9, 1984 - a full three months before it debuted in the States.
Rebecca Holden (April) celebrated her birthday during the making of this episode. She presented a K.I.T.T.-cake to the cast and crew.