I'm back with my dual 3.5" speaker brackets

Very nice! I'm glad you included the bottom view showing the spacers. I've been trying to explain that very thing to many of the folks buying my brackets. Some of them have resorted to enlarging the openings so they can slip the speakers in from the top of the bracket. My intent has always been for the speakers to mount from the bottom as you did.

Some speaker brands are designed with the center tweeter cones or the flexible rubber surrounds raised quite a bit above the mounting surface, causing them to interfere with either the dash grille or the bracket surface. Use of small spacers like you did eliminates the conflicts quite easily.

Thanks for the update.