Got it. Thank you. In the picture of your second layer of STP in sub trunk seem to be very flat. Did you use a plywood and put STP on top of the plywood? If you do, did you put any glue or something else to hold between first layer of STP and plywood?It's an extra security feature that I added. I wasn't sure if I was going to get a stable switched 12v (and Tesla can remap/disable some ports with OTA updates). So I've added this switch so I can easily change the configuration from automatic (12v switched automatically when I open a door and keeps it as long as there is someone on driver seat) to manual. For the moment, the switch is always set on, I've never touched it until now.
I need to do something like that too so I can fasten the screw for the amps and etc. into the bottom of plywood in the sub trunk. I was thinking to use this strong Velcro between first layer of sound deadening and plywood then put other layer of sound deadening on top of plywood.