Where did you happen to add butyl and ccf to the firewall and rear seat? I did the doors and the trunk, Honda didn’t have any insulation around the rear wheel well on the si like upper models do. Did you happen to take any pictures along the way? And last question, what materials did you use?Haven't seen anyone bashing - I will say that the different trim levels have different levels of sound deadening. The Touring models are downright quiet - hey have alot more of the factory "glue" on type of deadner on the panels, they also have additional sound deadening in multiple locations The test models were the touring in alot of areas. I came from a 335i and a 4Runner Limited to the Civic Si, it was Loud as shit to me - after extensive sound deadening and effort mine is just right now. All of trunk, doors, rear seat area are done in Butyl and CCF, I also added some butyl to the firewall. Made it great, will remove front seats and put out my remaning butyl and CCF under them.