I assume you know for a decade or more companies have been piping engine sounds into the car or applying vibration to the firewalls related to engine operation because they had made the cars too quiet and vibration free. In the case of Ford they were being cheats. 4 cylinders were getting made up V6 sounds, and V6s were getting V8 sounds. Even Porsche has an open pipe from interior to engine bay with a valve to open a modulate engine sounds that get in. VW and BMW had what amounts to speaker drivers without the cones attached to firewalls and programmed to provide the desired effect.