WITHIN 5 MINUTES OF STARTING THE VEHICLE I SMELT A BURNING PLASTIC ODOR WHILE ENTERING THE HIGHWAY. ONCE ON THE HIGHWAY I NOTICED MY A.C. WAS NOT WORKING, I ROLLED DOWN MY WINDOW AND ATTEMPTED TO TURN UP THE BLOWER SPEED. SHORTLY AFTER SMOKE STARTING BLOWING OUT FROM THE VENTS, THE DEFROST AREA, AND AROUND THE TOUCH SCREEN. WITHIN MINUTES THE SMOKE WAS THICK AND GREEN WITH AN ELECTRICAL FIRE ODOR. (I COULD IDENTIFY THIS AS I AM CERTIFIED THROUGH THE STATE OF MISSOURI, FIREFIGHTER 1 AND 2). I USED MY LEFT BLINKER TO PASS A VEHICLE TO EXIT THE HIGHWAY, THE SMOKE INTENSIFIED TO WHERE I COULDN'T SEE OR BREATHE. I EXITED THE HWY. I PARKED IN A PRIVATE LOT AND EXITED THE VEHICLE AS MELTING FLAMING PLASTIC WAS DRIPPING AT MY FEET, AND OPENED THE HOOD. NO FLAMES PRESENT UNDER THE HOOD. I LOOKED THROUGH THE PASS. WINDOW AND FLAMES WERE POURING FROM UNDER THE DASH WITH A STARTING POINT OF THE CENTER OF THE DASH AREA. WITHIN MINUTES THE VEHICLE WAS FULLY INVOLVED.