Take a look under your rear seat and the rear trunk floor and the unibody undercarriage. This car has NO unibody insulation. Drive over a gravel road- It's like being in an empty coffee can. Do a "search" or check out
www.raammat.com.
I did my entire unibody floor, 1/4 panels, wheelhousings, etc with insulation tiles and now it's quiet and tight as can be.
My one DIY thread has photos of the tiles before and after.