A system for detecting a vehicle occupancy violation includes an image capture module that acquires an image including a vehicle cabin from a camera positioned to view oncoming traffic. Gettering of impurities from a silicon layer is not interrupted by the oxide film since the porous silicon layer is placed above the oxide film. A capnut is associated with a distal end of the shaft for movement therewith. The interlocking elements extend through and interlock through engagement with another fence or the board.