So as the title states I am trying to put toggle switches where the HVAC controller goes. I’m just wondering if anyone knows of a pre-fabricated plate for toggle switches or just for a delete plate. one that can replace that HVAC and has the little 90° brackets to mount up to the back of the tombstone. If not and anyone has some suggestions on how to fab one or what you bought to make it work let me know. Open to all ideas.

Just a picture of a universal one I was looking at.

 

It should be just like making a simple radio block plate.

Cut a square of alloy/steel/plastic to the shape needed, drill holes to take bolts where they line up with OEM holes.
if you need L plates just use extra metal and bend it in the vice to the shape needed.

 

I have toggle switches and all i did was made a radio block plate and yank the head unit. I assume the climate control slot would be pretty much the same ordeal.
as far as off-the-shelf, i dont think anybody would bother to make a retail version of such a thing specifically for miatas.