A strut bar isn't going to improve anything. The Passport (and Pilot) doesn't have a chassis flex problem; the issue is the high-center-of-gravity, heavy weight, and soft suspension. Those are what contribute to the body roll, and none of that will get fixed with a front strut bar. In fact, generally speaking the only thing a front strut bar is good for is lightening your wallet
. Sway bars are infinitely more beneficial in keeping the car flatter while cornering, but thicker sway bars will negatively impact articulation which will make the car less off-road worthy.