Can anyone tell me the right way to fix this? Ideally, I want to source a new wall from a parts car if I can find one and have it sent to me, but I have a feeling it might be cost prohibitive.

/M

I may have that panel on a later s30 chassis. I would expect them to all be the same. As for replacing the entire panel, that's going to be a lot of work. There are multiple layers at the rear of the transmission tunnel that would have to be separated and multiple layers out near the wheel wells also. If you separate all of those to get the panel out you are going to have to take measures to keep the car straight. If it were mine I would never consider dealing with the 200 or so spot welds to fix the speaker holes. You could either get some one to make you some patch panels with the correct beading or you could get a factory panel and cut your own patches out of it. In the end it's almost all covered anyway...

Urg. Yeah. Sounds like match panels are the way to go.

/M

Ya I'd find a doner car and cut patches, and clean up the cuts they made so you can get a smoother weld.  aleast you can access bowth sides so you can crush weld the panel.

Speakers?!  If it were me I'd rustproof everything I could get to inside the holes since you have access and then weld in a sheet metal patch.