aliphatic resin(wood glue) is stronger than wood itself, and seeps into the woods surface, making a way stronger bond than any screw. i build high power model rockets and thats what i use to flush mount fins to the airframe...some of these things travel at over 700mph, just to give you an idea, and the glue is the absolute only thing holding it in place.
BTW, looks nice and clean, if this is your first custom install, it came out real good, only thing is the crossovers, i'd definately have those babies up front. but other than that...looks good...