An isolation structure comprising a substrate is provided. The base body includes a first face having a first region corresponding to a lamp and a first peripheral region disposed around the first region, and a second face having a second region corresponding to the first region and a second peripheral region corresponding to the first peripheral region. The PV solar cells and the LED lights are self-contained in a rectangular plastic housing. In cold weather, the auxiliary power unit maintains the primary engine coolant and lube-oil warm to facilitate engine restart. The first shoulder is structured to rotate independently of the pin and the second shoulder.