I started cutting out the bad metal in the back seat area against the inner fender wells. This section isn't all that bad overall, just a few pinholes here and there. I also cut out the bottom of the dividing panel between the cab area and the trunk so I could get in there to blast better. There was rust between the layers that had to be cut out anyway.
More inner fenderwell rust at the bottom edge.
Trunk divider bottom cut out.
Beginning to make a new panel.
