A cargo bed for a utility vehicle includes a bed portion including a left-side wall portion and a right-side wall portion and a rear opening between rear ends of the side wall portions, and a tail gate to close the rear opening of the bed portion. Embodiments of the media processing system include an audio processing subsystem that operates independently of the host processor for long periods of time, allowing the host processor to enter a low power state. A switch or a demultiplexer capable of detecting congestion. Also, the method can increase work efficiency and further downsize the integrated piping plate. Output signals obtained by the switching in accordance with the first and at least one second local oscillator signals are summed and the polarity of one of said first local oscillator signal and said at least one second local oscillator signal is switched in response to a control input, to thereby switch between a harmonic-rejection mode and a sub-harmonic mixing mode. Multiple embodiments provide that the means for imparting an oscillating motion impart at least two speeds of oscillating motion.