You don't get the usual rumbling of an idling engine, just the whisper-quiet whirl of the e-tron's motor (Audi is currently engineering an "e-tron sound" so that outsiders will be able to hearthe car) and wind whizzing by.
This year, 18, 000 people came to hearthe music, eat jambalaya, and watch the Budweiser Clydesdales wind their way through booths selling succulents, tie-dyed t-shirts and Avon products.