Dr Pinky can confirm Leyland, you don't have OCD. Car parts don't go on beds if you've got OCD.
Craig is right about different ways to stop sound. I did the wheel well, rear panel, arches and under the rear bench in my SC. The subwoofer made every thinner bit of steel resonate. I used Dodo stuff. Combo of deadener mat and closed cell foam. It does make sounds from other sources more apparant.