Jacks just make it easier. there are two things that make you go under the car:

1) taking off the bumper (well, not hard at all really to take this off without jacks)

2) one bolt that's hard to reach/see from the top: the bolt that's 1 of 2 bolts that holds the bracket that the bottom of the stock air box is connected to.

(oops... forgot which forum I was in, this is for a 6th gen civic... sorry)