The access hatch has turned out to be a really great idea. This will allow a total air tight seal around the cooler and a much easier way to access the air filter. Boom! I first laid up 3 plies Carbon over the bottom of the plenum box and baked it in the oven. Then I removed it, trimmed it up and cut out the access hole in the bottom of the plenum to suite the new K&N Filter that should arrive tomorrow. I was concerned that I wouldn't have enough room for nutplates but found that #6 plates would work, but barely. I chose to install 4 to begin and see how flush it turned out and it actually worked out pretty dang good. I "may" add a small lip around the perimeter using micro, or even just let a bead of rtv cure in place. Either way, it's gonna work out nicely. I also laid up a 3 ply Alternating BID square of Carbon that will be used for the alternate air reed. The first one I laid up was pretty rigid, but James Redmon says his worked great. Although he used 2 of them. If this is too stiff I can easily sand it down until it submits! However, the chances of needing alternate air are EXTREMELY slim considering the fact that I'm using a NACA duct on the bottom of the aircraft. It would take a large bird to plug the duct. Chances are that it would go through the prop before entering the duct. Either way, this will be peace of mind :)