Cars typically put out 60 kw of heat. Even on the rare occasions motorists stop at red lights they are still emitting 5 kw on idle.
Do we really need all this unnecessary heat?

If the car is burning fossil fuel after about 10 years the solar heat the CO2 in the exhaust has trapped is about the same as the original heat of combustion, after 20 years it's 2X as much heat and so on.

Today the heat of combustion represents only 18% of the total heat from by past and present burning of fossil fuels.