Exhaust manifold heat management

The big exhaust manifold produces a lot of heat. Most of it finds its way to the driver's feet and legs. With the narrow body and the gearbox sitting midship, summer drives closely resemble a sauna trip. Adding this panel helps to derive hot air from the engine compartment to the outside. The opening is there since the rebuild and is not original (like so many things on my car). Test drives show improvement, but I'm also tempted to add more heat insulation.
Cheers.