"How much CO2 was generated in making the new cars? How much CO2 will be generated in making the new cars to replace the ,now empty, dealer lots?" Nitpick: You

"How much CO2 was generated in making the new cars? How much CO2 will be generated in making the new cars to replace the ,now empty, dealer lots?" Nitpick: You're counting those emissions twice. You can count the CO₂ emissions either when the car is sold ("how much was generated in making the new cars") or when the car is manufactured ("how much CO2 will be generated in making [their replacements for the lot]"), but not both! If it isn't clear why, consider that in the future, those replacement cars will be sold. Since you've already counted the CO₂ to make them, you clearly can't count it again on sale.