Can't go wrong with the plate. The mount is sturdy but the plate completes the bottom so the whole thing is a boxed frame. If not, swap the smaller washers with fender washers to distribute load around the holes.
RAM Mount balls and arms for cell phone, travel trailer rear camera screen, and dash cam. Yes, the 2nd pic is under the bottom of the dash tray. Self tapping screws would probably work for light loads. I'd put some high temp, extra strong double sided tape between the mount and the dash tray just for extra security.
Yes! Auxiliary power in those areas would be nice.
Here are some more details:
Full picture of the bottom of the dash tray.
Holes were drilled to 3/16" instead of 1/4". The 10-24 screws fit perfectly with clean holes.
View attachment 41469
The three clips are located where each of the trim tools are. When popping it off, I placed a microfiber cloth between the tool and the surface to protect it from getting scratched.
View attachment 41470
What is looks like under there with tray off.
View attachment 41472