Being a Mazdaspeed 3 owner, just adding an intake, downpipe, and 3" exhaust landed almost 40whp on the dyno. I don't know where your looking but there's tons of aftermarket support for mazda. You have racing beat, cpe, protege garage has an excellent selection of parts, auto exe makes the bomb shit for mazdas. As for the 6i, You have a little 2.3l in a huge sedan, now the 6s with the 3.0v6 is fast. I smoked a new v6 mustang with the mazda 6s rental we had all the way to 140. I will agree that for tuning you have to rely on stand alones such as haltech, aem, etc, but they are still very tunable and there handling is almost unsurpassed.