Not kidding. And not for Sevens

[A G Wood]

Ford, as an example, has an obsession with NVH, and as a result made the previous model ICE Mustang too quiet for a 'sports' car, according to their customer feedback. So the latest iteration of the ICE Mustang had a diaphragm sealed tube set in the firewall to deliberately conduct a controlled amount of engine noise back into the cabin.
The Mustang Mach-E (the electric one) has a quite sophisticated user-selectable synthetic engine noise generation system that the Detroit engineers seem to be proud of, a good example of what Bob's book is talking about.