It is fairly strong. I bent it from a flat piece of aluminum. The hardest part was getting the correct angles so that the top of the plate was horizontal.
It is hard to tell in the first photo, but I have a spring base, so I don't have to worry about hitting things.
The bracket is grounded, it is screwed to the chassis. The wire you see is the shield wire for the antenna cable which needs to be grounded at the antenna base. Don’t forget the center piece is not to touch the ground anywhere. There is a piece of plastic between the bracket and the part the antenna screws into.
To get the cable inside, there is a rubber plug right in the top left corner above the hood release.
Richard