dampening

As much as possible isn't the way to go.

check out Sounddeadenershowdown for some good tips to be efficient with dampening products

i just used some cld tiles on the trunk lid and floor of my car, was easy to work with and a great hold. would recommend it all day

on a car like that (light one like civics and yours) do the heck out of your trunk lid as tha will vibrate the most.. i personally reccomend fat mat extreme its just as good as dynamat just your wallet doesnt hurt as much. be sure to prep the spots with a degreaser then an acetone which helps for the initial and long term adhesion factor.

be prepared to spend a full day on this project if you want it done right

Examples of Sound Deadening

Car Stereo Talk.com • View topic - Sound Deadening

^thems the old school unnecessarily excessive way to deaden.