There is this one (for all Mazda family) and another on-line forum that deals only with Mazda 3s, but I definitely like this forum much better. I've seen too much childish behavior on that forum that pretty much goes like, "I disagree with you, and you're retarded", "no, you're retarded", "you're gay" and so forth. -_-;;
Welcome to the forums and ask away! (not to me though 'cause I'm no expert =P )