Cool thing about the turbo kit is, It will void your warranty on every inch of that car. If you want turbo, Just trade in your 03 - 05 for the 06' Mazdaspeed Turbo.
The Auto tranny won't handle the turbo power, it's only rated safely up to 200 HP. I am pulling 190 HP out of mine right now with the Injen cold air intake, spacers, TB bypass, Custom Monza exhaust with Hi flo cat - My tranny is showing severe signs of slippage when getting up into higher rpms. I would only recommend this on the 5-speed 2.3 applications.