1990-1993 Ford Mustang White Heater Overlay HVAC A/C White hvac controls are made with the same quality plastic material our white gauges are made of. Each white heater control is specialty printed, laminated and then computer cut for a perfect fit. Some white hvac's go over the top of your stock hvac and some replace the entire face, view install instructions for info. Manufactured with a special process so overlays are transparent and use the stock lighting to light up at night.