Any proven methods for removing the glue on the interior firewall behind the backpad? Stripping down to bare metal is a nuclear option that I don't have available to me right now.

Goo gone isn't yielding much results after soaking it. This has become frustrating.

3 m adhesive remover.
Then laquer thinner

I with that for a few days. Looks of recommendations but nothing with results. Goo be Gone was as effective as a water pistol in a holdup. I even tried soaking rags in the stuff and left applied for hours. Zilch. Lacquer thinner, paint thinner & acetone softened the stuff but you need to be careful or you remove paint too. I never tried MEK. I finally said it and took pics so the next owner could see that the paint was very nice and the sound pad wasn't hiding rust. I don't think Grandma's Lye Soap would get this off. Your results may vary but I doubt it.

You might try adding heat.

Most adhesives get softer, more pliable the hotter it gets.

Sometimes heating to the point of no touching and then holding a piece of dry ice against it can help (thermal shock!).

I have a bad-assed German heat gun that can sear steak (1100 degrees) but often a simple hair dryer will work fine...

Hey honey, can I borrow your hair dryer!

Mine came off real easy with a grinder

I haven’t removed the glue on the firewall, but I recently removed all of the headliner/pillar glue in my Westfalia. I found that using a slow reducer worked best. It says wetter, longer than other options like acetone, thinner, MEK, etc…. allowing the adhesive to soften. I scrubbed with steel wool and wiped off the hazy remains with a soaked rag.

I had the best success with Turtlewax Label and Sticker Remover. It comes off slowly with a lot of elbow grease, keeping the rag wetted etc.

Maybe 2 sq ft per hour - not fun, but the paint remain fully intact.

https://www.amazon.com/Turtle-Wax-T-529-Sti...r/dp/B004M3F5CO

3m adhesive remover.

I did the entire back seat area, and floor, and rockers...etc etc etc
on a 911.
Its the same glue.

Just wear some great mask...the stuff is not cool for the lungs/brain.

Takes time...wait...wipe off quite a bit, and it does sort of smear things around that end. That is when lacquer thinner helps clean it up pretty.

Takes a few hours...not worth ruining things without trying it first.
Go to a DECENT auto body paint store...they have what you need.

Acetone will work...but if left on it will lift the paint.
Laquer thinner can lift paint...but that takes a long time
Oddly, brake fluid seems to lift paint also.

Rich

Brake fluid will seep into the metal and is damn difficult to remove.

Sometime after the paint job your paint will bubble...

Never use brake fluid for anything but brake hydraulics!