WHITE AUDI E-TRON: This is not surprising. EVs are inherently quiet due to the absence of controlled explosions under their hoods, which is why safety regulations now require all new electric vehicles to hum like spaceships at low speeds to avoid running over pedestrians. But Audi deserves kudos for refining the e-tron’s aerodynamics so as to generate almost no audible wind noise at speed. In addition to laminated side window glass on higher trim levels, there’s enough sound insulation packed into the Sportback’s structure to account for a good chunk of its massive 5819-pound curb weight. Tire roar on the highway is faint, and even rough roads and pavement seams produce only distant thumps from the wheel wells.