Appropriate sound - In Sept 2018 the new WLTP (World harmonised Light vehicles Test Procedure) was imposed as a result of the VW emissions cheating scandal.
The WLTP rules compel all car manufacturers to ensure that their vehicles comply rigidly with worldwide harmonised noise regulations. The practical result is that cars manufactured after this date are significantly quieter. And... the simultaneous imposition of particulate filters makes them quieter still.
For many citizens this is desirable, but for enthusiast drivers the sound is an important element of the experience and almost no one wants a silent Sports Car (even electric vehicles are being saddled with artificial soundtracks).
The QuickSilver 'Sound Architect exhaust for the Yaris GR should please all enthusiasts with it's bass-heavy presence and rising note under acceleration - With nice turbo wheezes, even Tommi Mäkinen would be satisfied.