Hi Jason:
If you were to prioritize your desires regarding the noise, exhaust note and heat, which is most important to least important?
1) Beefier Exhaust Note
2) Keep Exhaust Note Outside of Car vs Inside
3) Provide Barrier for Thermal Heat from Motor
4) Provide Heat in Winter
I am not sure there is one good solution (manifested as a single product) for all four of these. And #2 is probably impossible to attain (have you tried ear plugs?) while 3 and 4 seem contradictory. 4 can be achieved with the installation of a heater.
As for 1... add one Big Block.
