When someone has previously called shotgun, and then gets out of the car at all, without calling seat-back. The person who wishes to obtain the position of shotgun shouts "shotgun hi-jack" and takes the shotgun position.
Joe's homey get's out of the car... like a fool he doesn't call seat back... Joe being the genius he is calls shotgun hi-jack and takes the shotgun position. Joe's homey returns to the car... and realizes he is a fool and sits in a non-shotgun position.
by jhirbour June 2, 2011