Audi knows sound, and it wants its upcoming plug-in cars to have as distinctive a grumble as possible, just like its fossil-fuel-burning brethren. That’s why Audi engineers are working on “new sound signatures” for future e-tron models. You can tell how seriously Audi is taking this by the way it references the sounds a car makes to music and “emotional sound structures” in the press release below. Funk Flex