I didn't read thru the whole discussion, but if you are going prefab I think the looks will sell more than numbers for a prefab customer. I was thinking of kerf pre fab boxes which you dont see anywhere. If you make like a vvx 12 kerfed box or a sundown sa 12 kerf box kicker cvx kerfed box, type r kerfed box etc... I think this will sell better than prefab. just my opinion.
I know the owner of Live Wire in Tampa and car tunes in Brandon, let me know I can have you meet up with them.