In addition to controlling the Light Bar, you have the option to disable the car's original Center Mount Brake Light (third brake light) when the Light Bar is enabled.  Connected this way, the third brake light function switches between the light bar and the original center mount, depending on the position of the convertible top.

Installation is simple.  The unit connects to the convertible top motor to sense when the top is up or down.  A connection is made to the light bar to enable or disable it.  With normal hand tools, installation takes about an hour.