what is the best way to mod my rx8 for cheap?

best thing you can do for a rotory motor is aftermarket intake and exhaust the better the motor can breath and exhaust the more power it will make

premium gas, Most exhausts and intakes dont raise HP like the do in piston powered cars, if anything its 5-8hp or if that, some exhausts even lower your HP, Mazda designed everything very well and at the end youll be spending 1-2k. Personally if im spending 1-2k im spending it on a set of coilovers or rims or a MazdaSpeed bodykit

I appreciate it. Idk what Im gunna do. I think my first thing is cold air intake and some new rims

Dont go cheap. The extra dollars will be well spent on a quality part if you choose to spend the extra money for them, you will see a significant change in performance if you choose to go with a more expensive part try Mazdaspeed, REAMENIYA, Racing Beat, Cobb, GREDDY, Black Halo Racing, tanabe or Petit Racing most of these companies started out on only rotaries so they know what is right for yours.

A nice set of tires is the first performance mod you should do to any car, I think. Check tire rack and filter down their categories to find some good summer tires. I wanted the Continental Extremecontact DW, but those were out of stock so I settled on Hankook Ventus V12s. They're good tires (at least they've been for the 7K miles I have on the car since then) and even in somewhat wet roads you're absolutely glued to the pavement. As far as power goes, though, this is a tough car to get more power out of. If you want straight line tunable speed, you're better off with something with a turbo, like a WRX.

I have had good experiences with INJEN intakes they are engineered directly for the application in which you need. Gas mileage increase as well as hp and not that price..