Die Hard
right, up, down, E			god mode
right, E, down, O			50 grenades, smoke bombs, and more!
right, up, down, down, E, right		change guns (repeat as necessary)
Die Harder
right, up, down, E			change guns (repeat as necessary)
right, up, down, E, E			god mode
right, E, left, O, A, down, E		extra missiles and grenades
Die Hard with a Vengeance
left, O, up, down, E, right		unlimited lives

Die Hard
right, E, E, down			fat mode
right, up, down, down, E, right		unlimited weapons
Die Harder
down, A, right, E			god mode
left, A, right, down			keeps aim from automatically shifting
down, E, A, down			skeleton mode
Die Hard with a Vengeance
E, O, X, O, E, L, X, D, L		affects other cars once they are hit