Spent the whole weekend pulling my interior for a deadening job

Did the same project in my old Civic a couple summers back and your back pain comment hit home. I did mine in sections because I made the mistake of tearing everything out at once and then it sat half finished for three weeks while I procrastinated. If you can ever do it again, just pull one seat at a time, treat that section, bolt it back, move on. Sucks to redo the work but at least the car stays drivable. Funny thing is I found the doors made a bigger difference for me than the floor did. One layer on each inner door skin and the highway noise dropped about as much as the whole floor treatment did. The metal in those door panels is paper thin and it rings like a drum without anything on it. Also learned the hard way to warm the pads with a heat gun before pressing them down. I laid half my first roll in the cold garage and a bunch of edges lifted within a month. Had to peel and redo them with proper pressure. A roller helps a ton too, even just a wooden one. Agree that the wire run while it's gutted is the best part of the whole job. I added an extra run to the trunk for a sub amp I didn't even own yet, and two years later it saved me from pulling carpet all over again.

Interesting that you went full MLV over the foam. I did my wife's wagon two years ago and skipped the MLV entirely after reading a bunch of mixed experiences on it. Just did butyl on the floor and rear wheel arches, then a layer of foam with foil facing over the top. The difference was honestly smaller than I expected compared to my buddy's truck where he did the full sandwich. His trunk area made more difference than his floor did, so if I ever do another one I'm spending more effort on the rear quarter panels and the hatch area than the middle of the cabin. The other thing I learned the hard way: wear gloves you don't care about. The butyl got on everything, my hands, the seatbelt anchors, one of the door jambs. Took months for those smears to stop showing up. A cheap roller from the hardware store beats trying to press pads down by hand too, I started with my thumb and ended up with a bruise the size of a coaster.

Agree with the other poster about doing it in sections though. I had my cargo area torn apart over a long weekend and it became the garage storage shelf for a month before I finished it.

Curious how you handled the transmission tunnel and the area around the shifter boot, since that's the spot where I always second-guess myself. I did my sedan last fall and left the tunnel mostly bare because I figured the heat from the exhaust would eventually cook the adhesive and make a mess, but now I wonder if I gave up a decent chunk of improvement for nothing. Also, did you notice any change in how the car feels at idle, or is it purely a road speed thing? Mine got noticeably quieter above 60 but the drivetrain hum at low speed is basicly untouched.

The adhesive gunk cleanup part is underrated misery. My floor had some rubberized undercoating the previous guy slathered everywhere and the degreaser just smeared it around. Ended up using a plastic scraper and letting the stuff sit dry so it flaked off in chunks, way faster than trying to dissolve it. Also my tip for reinstall day is to take photos of every wiring route and seat bolt orientation before you pull anything. Sounds obvious but I still spent twenty minutes staring at a harness clip going 'where did this even go'.

Update: tried the dry-scrape trick someone mentioned, letting the leftover adhesive sit and then flaking it off in chunks with a plastic scraper. Worked way better than smearing degreaser around, got the last of the floor cleaned up in under an hour. Still doing the whole job one seat at a time next go, my back can't take another full gut. For anyone who skipped the MLV, did you notice much difference on the highway, or mostly around town?