I just put a cold air intake on my girls auto miata. Oh yea. That thing has way more power. Before the cold air it was restricted bad. Now it runs like a bone stock 5-speed. Of coarse it won't burn tires. But at least I can pull out in traffic now.

 

On an auto it would be negligible, you may have just been better off changing the stock panel filter. Mazda engineers did make it to pull air from the outside. Also you gotta deal with header heat if the intake is unsheilded. More heated intake air = less power. Just my .02 though. If a cone airfilter makes that much extra HP good on ya.

 

I still have the stock heat shield on the manifold. Besides the cold air looks cool and was free. I took it and a strut tower brace off a miata I'm selling. I can't wait to get exaust on it.

My brothers are in town so mabe I'll be able to get my turbo on my 5-speed Mon.