When washing my car at an automated car wash my brakes failed when exiting the facility. When the wash was completed it gave me the approval to leave. I tapped on the gas pedal to get the car moving slowly. The car started to move down the ramp and when I applied the brakes there was no response. I pumped the brakes several times but they did not engage. I tried to hit the parking brake and shift into reverse and nothing happened. I finally had no choice but to hit a wall to keep from hitting a vehicle. I did contact the dealership and they were non responsive. They indicated they had never heard of a wet brake issue on this vehicle. I provided them with several statements from the EV6 Forum. My vehicle had less than 600 miles on the odometer.