The Photoshop is only a sketch idea. Just a suggestion.
No, don't block the whole engine bay. Need opening for venting air from the covered bay area direct out to the top of the hatch. Need opening for oil change and oil check...
Need fans on side vents to provide continue air flow for the bay.
But not sure how much weight will add
Or may be a small bath tube shape heat shield that can sit the intercooler in to shield off the heat radiation from the engine bay.
Check out these:
ACL Race Series Heat Shield Material Clevaflex - Applications Both can easily form fit no need to have special equipement, just need cutters.