A method for detecting vehicles with cargo in a traffic telematics system comprising at least one radio beacon for radio communication with onboard units carried by vehicles and their cargo. The upper cover includes an outer surface having any of a variety of decorative displays, a top portion and an open bottom portion. The photosensitive material after said first exposure includes one or more under-exposed or incompletely exposed portions or one or more portions prone to peeling. The housing further includes an integral MP3 docking station for receiving an MP3 player therein for receiving music from the CD placed in the CD receiving station. The controller is also configured, if the combustion engine is operating under the desired rich fuel condition, to monitor a catalytic activity within an ASC assembly that converts NH3 within treated exhaust gases from the combustion engine into N2 to determine whether the catalytic activity has been deactivated in the ASC assembly. An computer chassis may comprise: a computer chassis body; and at least one rotatable handle.