dampening

I've read through about 20 threads from a search on Spring Rates in this section but still could not find the info I'm hoping exists. I did find the following link but seems to be only for the coupe...

To be clear... I love my Genny. I'm happy with the quietness. But as my wife will tell you... I'm all about trying to improve on perfection. It's my humanity :). That said... has anyone thought of adding sound panels above the wheel wells, in the trunk, any other place to absorb even more...