Hi, I though I might want to share my experience.
I sealed off the big cavity space above the rear wheel that link the boot into the cabin with expandable foam ( construction/marine foam spray can ). You will need to remove the plastic panel below the quarter window. It seal out noise and smoke from the engine bay too. I also filled the chassis structure with expandable foam too. Together with those recommended panel deadening with Dynamat especially the back firewall, get the thickest on the panel. Its worth all the effort doing it.