i have supersprint on mine and like the way it sounds. its a little deeper sounding, but not that much louder than stock. help low end power a bit, nothing huge though.
1991 318is aka: the torque-less wonder!
mods: TSW Hockenheims, H&R springs, Bilstein shocks, Supersprint exhaust, Jim Conforti chip, K&N, Z3 short shifter conversion, custom made strut tower brace
1988 Ford Ranger STX