I put dyna-mat under the rear seat, and up the axle well behind the rear back rest, jute behind the devider board. much quiter inside the car now. There's still a very faint drone at 45, not obnoxious but I can tell it would be 100x worse with out the deadner
Manifolds TTI 2.5" X-pipe Dynomax muffs
Current cars: 2000 Dak Quad Cab, 2012 Challenger,1970 Road Runner, 1994 Firehawk
1966 Coronet post sedan, 1988 Corvette, 2005 Magnum RT all SOLD