i just bought a mazda3 5 door and i wanna change the exhaustmaybe around 600-1000 dollars would be good
megnaflow is always a good choice but its really the type of sound you are looking for
Its personal preference. Someone might tell you wow X exhaust sounds awesome! and to you it will sound horrible. Go on youtube and search mazda 3 exhaust and see what videos pop up. Watch multiple videos on the same exhausts to get an idea of what they sound like.
