Oh yea. Little outside noise but big inside air displacement!
I ran free air subs mounted to the back of the seats on 3/4 inch high density partical board. I used the whole trunk volume as a resonator. It put the natural resonace at least 10 times lower than the tuned port or band pass boxes everyone else was using! (Bigger volume = lower resonance frequency. Simple acoustics!)
I cut the seat foam out from the back to get the sound through without dampening it. The seat fabric was al that was in the way.
I put a lot of effort into that system. Everything but the reciever in the dash was hidden. I had a few friends with systems that had everything out in the open to show their stuff off. They all got broken into and stollen or trashed.
The worst I got was a poorly done keying at the mall parking lot on a sunday after noon. I knew the dumb **** that did it too. Monday morning he said: I see your car got keyed. I said: when did you see this? he said: I saw your door this morning. It must have happened over the weekend, huh? (with a grin in his voice.)
I said, no it didnt. I washed it last night. I would have seen it. Its just fine!
(When it got keyed the doors were so dirty the key never actualy got to the paint. I washed it that night to see what damage there was and there was none!)
There was no way anyone ever saw the actual key marks so knew it was him.
He was from rich family too and got everything handed to him. My car sound system beat his easily! It made him way jealous that a poor farm kid had something he couldnt have! (Brains and skills!)
I never rubbed peoples noses in it that I had the best sound system in the town though.
I always showed them how I did it and often got paid well to redo others systems to work better.
Plus that paid way better than the 80 cents an hour my dad gave me for hard labor.
The kid that keyed me? Well I got him back with interest! At a party a few weeks later I shot a half a can of brake cleaner down his intake with the engine running. Any guess as to what that does to the O2 sensors and catylitic converters?
Piss poor mileage and a big non insurance claimable repair bill shortly follows!
Dont mess with us nerds, we use science to fight dirty!