According to Turbo Mag, SR Motortsports here in Cali already has a full cat-back exhaust system for the MP3 available and it's 50-state legal. It supposedly give a deeper more aggresive exhuast note. Traditionally, when I think of that bumble bee sounding exhaust. I think it's a car with better top-end speed. Lower tones make me think of low end, mid range monsters. 
