This could pose a potential hazard
Yes, engine sound is a factor for auto manufacturers and designers of exhaust systems. However, there is a big difference between tuning the engines sound with exhaust pipes, and playing a recording. Perception is an important feedback to a driver on a busy road at moderate to high speed.
To introduce an artificial sound of the engines performance would be detrimental to driver's reaction and response in critical driving situations.
Yes, marketers are correct. Perception is everything. Law enforcement also considers perception as very important and it's why citations are issued and arrests made when it's distorted by text messaging, and DUI.
An auto manufacturer considering the introduction of this kind of marketing needs to stop giving relevance to stupid marketing ideas thrown out at cocktail parties, and reconsider what it is they're building and providing their customers.
It will also save them embarrassing reviews from motor enthusiast magazines, and potentially even dumber law suits.