Premier Date: August 16, 2006
While the obnoxiously large, diesel engine-powered subwoofer that Jamie and Adam built pumped out a whopping 161 dBSPL at 16 Hz (a level comparable to those found in cars specially designed for loudness competitions), it caused the sunroof of the car to jar loose, allowing for the pressure of the sound waves to escape. Because of this leakage, not to mention the fact that the forces behind the oscillation caused the woofer to break apart, the speaker system could not possibly create the amount of intensity needed to cause all the windows to explode as the myth stated. A best-case scenario would involve only one window failing, thus creating a path for the pressure to escape.
As far as driving on non-"washboard" roads there was no solid conclusion due to a conflict of data. However, when they tested a "washboard" road, like one the myth originally states, the build team were able to confirm the theory that driving at a higher speed will indeed cause the wheels of a car to travel over just the ridges and not into the troughs, allowing for a relatively smoother ride.