Adding Speakers to the Duster Package Tray...

Hello All,
I know that when I was looking at the package tray options for my 76 Plymouth Duster there were package trays with speaker cut outs and package trays without speaker cut outs. My Duster does not have the cut outs but we thought we would just add them and redo the package tray with the intention of adding two 6x9 speakers. Now that I've measured everything out, it looks like the torsion bars for the trunk lid sit right underneath that shelf, how does anyone have room for those 6x9 speakers? Am I missing something?