I want to clean up all my wiring so I got an auxbeam switch panel. I was looking at the firewall thinking I could put 2 rivnuts in and secure the bracket like that I just want to know if there is anything behind there I should be worried about. I was gonna bend the tabs down so that they lay against the firewall and the box will lay flat.

 

Or do you think I could just weld the bracket onto there. Which way do you think would be better. Rivnuts through the firewall or using a flux core welder to weld the bracket down in a few spots

 

Rivnut or self tapper would get my vote...Welding is what's considered permanent and you might need the room for future repairs...Nothing behind there that would be a problem for those two options...I cut a hole in the top cowl in that area to access the HVAC intake to seal it up and rodent proof the blower...