Went a little crazy with the Dynamat
Pulled the carpet out to find that the old windshield had been leaking thus confirming my suspicions.

Rear right door was always the rattliest



Lined all outer skins in Dynamat Xtreme followed up with a 2nd layer of Carbuilders acoustic stage 2 liner on the outer skin.
Finished up with a single layer on the inner door skin before refitting the JL C3 650s
Lined the floor pan also as I was amazed how much vibration comes through while driving, This was the only time having a shitty centre tailshaft has helped find areas of the body that are subject to resonance and excess vibration. The S90 already has an amount of factory applied tar based deadener which has been applied sparingly, I cleaned up all surfaces before adding the new material on top. The added thickness is negliable, the factory carpet sections on this car are almost 20mm thick in some spots.
It was good before, now its even better.
Weight added will be about 25 kg, the roof is next.