Day 101... decided to make a new hole in the floor:
Trying to work out how to remove the old arch spot welds and got distracted making sure there's some actual metal to weld the new one onto:
Had to leave it like this for the day hoping it survives the rain. Big welding blobs are where the patch piece had a large gap and I had to battle filling it and burning through rusty old metal:
Looks like the rust on the arches forms where water soaks into the factory grey foam. I'm thinking of just removing it all but is this here because of some sound resonance issue? Should it be replaced with sound deadening?
MOT next week and I'm very worried