Recently got hold of a new E-Tron 55 Sportback. One thing I've noticed is that when accelerating or regenerating at speeds of around 20-30 mph, there's a subtle but noticeable engine noise. Sounds a bit like a cross between a jet engine and a dentist's drill, although of course much quieter. For a car that has a reputation for being very quiet I wasn't expecting it. Is this normal for all EVs? I don't think it's an added external sound as I thought UK cars didn't have that. If it is indeed normal, I dread to think what Te$las must sound like...