This informal document GRSG-131-20 presents an artificial intelligence analysis of energy waste and CO2 generation by poorly insulated or uninsulated cars. The analysis compares cars with good roof insulation (metal roofs with 2-3 cm foam/felt) versus poor or no insulation (glass roofs or thin headliners) across 20,000 km annual driving. For gasoline cars, poor insulation wastes 70 L/year and generates 175 kg additional CO2. For electric vehicles, it wastes 200 kWh/year and generates 100 kg additional CO2. Across a weighted fleet, poor insulation costs $61 annually per car. Globally, approximately 600 million poorly insulated cars waste $36.6 billion annually and generate 91.2 million tons additional CO2 yearly.