Hi JJW
The Roadster Sports had (for me) a drone issue in a very sensitive rpm region. So I let built new exhausts for her to solve it.
The Plus4SS has only one exhaust line. And you can cruise with a really not too loud car. But yes, under full throttle she can become (very) loud but she is not unnerving at any revs. Only the open throttle bodies (which are on the left side, and car is LHD) can smash your eardrums between 2500 and 3000 rpm with very short clatter attacks. It´s interesting that when sitting on the right hand side this sharp throttle body clatter is not audible.
