brush guard rattles

i put a brush guard on my 01 4runner and the thing rattles when i hit any bumps or go over 70mph. its got about a 1/4" clearance on the front fenders and thats where it hits. ive tighten all 10 bolts on the thing to about 600 foot pounds and it still rattles. what am i missing? any help?

Try taking it off and elongating the mount holes with a rattail file so that it will clear your front fenders by 1/4" + 0.001" (or whatever it takes).

Alternatively, put a small piece of soft stuff (styrofoam sheet, neoprene rubber sheet, anything that is weatherproof and won't mark your finish) between the fender and the brush guard at all the contact points.