it works your suspension crazy like. i have a pretty heavy woofer and it dropped the back end like a 1/4-1/2 inch. i think my struts are done, in the rear anyways.
woofer = 42lb box = 25ish lb amp = 3ish lbs.
i donno how heavy that kicker and box is, but good luck with the rear suspension. that's a very nice woofer tho.