I need to remove the plastic piece on the underside of the rear strut bar. My sub box fits tightly under there against it and rattles like CRAZY because the box transfers the energy to the plastic... and ideas?

 

Some sort of foam insulation may be easier?

 

Heh, I was just gonna let this post drift off the map and disappear without a response. For those interested, I ended up removing the underside panel of the rear strut bar. I gained about 1/2" clearance, and it is NOT noticeable unless you stick your head in the hatch and look up. I also noticed the rattles aren't from the car, but from air leaks due to the subs not being entirely sealed into the box. MUCH easier problem to fix. I am, needless to say, a happy man tonight.