Not sure why but some of the pictures recently started showing that didn't before.
The place you are grounding your amps on the body is a bad grounding location.
If you notice in your pictures the body panel you are connected to is connected to the one below it by spot welding and sealed with seam sealer. That type of connection is a poor ground transmitter. You need to find a location that is either part of a continuous piece of metal connected to the firewall where there is a current main ground, the frame assuming the frame is grounded or run directly to the battery.
The place you are grounding your amps on the body is a bad grounding location.
If you notice in your pictures the body panel you are connected to is connected to the one below it by spot welding and sealed with seam sealer. That type of connection is a poor ground transmitter. You need to find a location that is either part of a continuous piece of metal connected to the firewall where there is a current main ground, the frame assuming the frame is grounded or run directly to the battery.