2019 Audi e-tron quattro prototype drive - Why Namibia and why Bitterwasser? Simply put, this harsh and unforgiving environment presents numerous opportunities to test Audi’s fifth all-wheel-drive system, developed specifically for the all-electric e-tron quattro. The surface of the Salt Pan, made up of a mix of salt, sand and dust, closely resembles that of hard packed snow, and the over 35 degree Celsius heat is a good test for the two liquid-cooled electric motors powering the car.