I am not to sure that will help much and at least one member said it did not. I do suspect the bushings in the supension are transmitting alot of energy into the body which in turns causes the very powerfull hence hard to deal with rumble. Tire selection seems to be quite critical as across smooth pavement that type of noise almost completley disapeared.
A two edged approach is needed, do all you can with deadening then look for the quietest tires you can live with. I really liked my Kumho V700's, dead quite, sticky as all get out(not so great in the cold but suprisingly good in the rain even when no tread left) smooth riding, not to great in the mileage rating though
I did get a whole season of autocrossing, driving to events, alot of burnouts, many many autocross runs spinning madly out of the truns(better once I got the LSD to work but with 250 WHP in a FWD, going to spin them a bit here and there
Nearly 9k miles is not bad at all when at least half of that was wheel spin, lol!