Dave, My next-gen kick plates will also be for 4" speakers, because there is so little room behind them for the magnet. I'm not planning on producing them, just making a set for my car. I'm planning on making mine using paperboard, plywood, (for the ring), and epoxy filler for the radius blend. It's labor intensive, but I can do it in my garage. Then I'll paint them with textured black paint. Once I get the design finalized, I'd be happy to pass it on to you if you want to produce them. I think the best / cheapest way to make "production" parts would be thermoforming, and at $30/set could be profitable. If theormoformed, any suface texture of your choice could be achieved.