New here, hello.
With the advent of FI and MAF there is now much more to the engineering of air filters and CAI. Without going to great detail it is possible that a low restriction filter, or even the complete absence of one, may have a negative result and against expectations even lower the performance of the engine. The results vary between engines due to calibrations and so it is possible that filter brand X brings positive results on engine A while it yields negative or no results on engine B.
The one group of cars in constant search of power are without doubt the Spec Miatas that are strictly regulated and where even the most minute gains end up being a considerable advantage. The filter most commonly used here is the one made by Green Filter
https://greenfilter.com
BTW one can not trust the filter brand decals on the cars as you will often see brand X advertised due to racing premiums paid while the filter driven is the Green Filter.
If you buy it make sure that it is the genuine article as there are many imitators which perform poorly.
My own BRZ tS is less than one week old and it will remain stock as it will run SCCA Solo in the Street Stock class.