Grumpy Old Geeks Products Audi e-tron Product Audi e-tron 2 mentions in 1 episode The Audi e-tron is discussed for the sounds it makes while driving forward and backward. Mentions 359: 19% Upside? Jul 10, 2019 36:47 Audi's e-tron makes a hum when driving 37:05 when you're going backwards, it makes a different sort of hum