Or "Cooling Panel" as the website says.  I'll use it + some additional PVC plastic sheets to completely cover the openings in the OEM panel. My plan was to do this from the underside but this both looked OEM good and was not too pricey. The PVC will make it less rattly as well (if any)

It should look somehting like this when installed

Why did Mazda put those holes there in the first place ? It might be a way to draw air to the upper parts of the rad or something. Hopefully this will make more air go trough the heatexchangers.  I'll do some more ducting work when finalizing the IC and Rotrex coolers.