I am looking to buy an e30, plan on seeing the car in person in a couple of days, but there are some rust spots, battery tray in the trunk and one on the A-Pillar / Cowl on the driver side.

hoping it is surface and local, vs hole and wide spread/rotted.

how much of a PITA is it to be able to repair a hole if there is one? would i need to remove the dash to get access to it or can i access it if i remove the fender?

I found a lot of M3 rust in that area but typically more in the windscreen perimeter not really in this little nook.

any help or past experiences / threads would be helpful.