For a "Road" car, the 6"diameter (152mm) is the best-sounding exhaust I make for the Toyota-engine models! When the 2nd cam kicks in, the scream is sensational. The N/A cars certainly have the edge on exhaust sound over the supercharged cars IMO.
You can drive through town/suburbs with no problems - it's not an obnoxious sounding exhaust - and it doesn't dronnnnnnne at all.
If you are a trackday enthusiast, or do a lot of motorway miles, you'll need the quieter 7"diameter (178mm) system - still a great-sounding exhaust but doesn't scream so much.
If you run at Bedford (UK track, very strict on NOISE) you will need the bigger, even quieter 8"diameter (203mm). This one doesn't scream but it does have an addictive howl on the 2nd cam!
Big oval tip as standard - or you can spec the twin-tip layout.
Choose size: 6", 7", or 8" Diamter