A couple of you have voiced concerns that the brackets must be removed , this is necessary , I tried to make a box which kept them , only to find after building one , that the box could not be installed without removing the dashboard first!
For those worried about removing the brackets , here are a few options -
1) You can carefully drill out the spot welds , then later they can easily be welded back on by any machine shop or a boat shop (they weld aluminum) - one zap from a welder each!
2) Forget about it entirely , since no one will ever know the brackets are missing but you...
3) If you ever sell the car and want to go back to stock , just re-install the Bose enclosure , the upper brackets and the metal plate will sit under the carpet just the same and no one will ever know , I have personally seen this in a couple NSX's.
This enclosure is designed by me based on the shortcomings of other box designs I have seen , some of which go against all enclosure design theory , which can in no way provide good performance.
I did really want to keep the brackets , but in the end it was not meant to be.