Anyone tried venting through the top of the firewall into the wiper cowl? I absolutely HATE the look of louvers or hood vents so I want to keep it as minimal as possible.

 

That's a high-pressure area, so that will only make any cooling issues worse at speed. The hood vents go where they are because those are the low-pressure areas of the hood. If heat soak is an issue and you don't want vents, then propping open the hood is always an option.

 

Interesting. I guess I don't understand the difference between holes in the top of the firewall and holes in the hood...five inches away. How are there different pressure zones that close to each other?

 

Here's a PDF document from Flyinimata with a pressure map on NC/NA. Should be similar for NB as well.
https://www.flyinmiata.com/support/i...sc/louvers.pdf