it’s bundled with their “noise cancellation” and it’a a package deal. If you disable the enhanced engine noise, you disable noise cancellation. Don’t worry, it’s not Bose quality noise cancellation.
It does work and if you have the stock exhaust it does change the cabin “tone” of the exhaust. It also covers some minor chirps, whirs, squeaks, rattles, knocks and minor NVH. It’s really minor, but, the ‘Rap has a really good ride quality and sound deadening so it’s easy to get used to that.
disabling the engine noise augmentation and noise cancellation will change the character of the exhaust note, and uncover some driveline and road noise you didn’t hear before. This is all very, very subtle stuff.
I did not think that disabling the fake noise/cancellation made the cabin sound ‘better’, but I also didn’t think it sounded worse. There was some additional in cabin noise at a VERY low level, but not worth going back in FORSCAN to undo it. YMMV