One cool day you get inside your car and notice warm Why?

The reason for this phenomenon is due to the greenhouse effect. When sunlight enters your car through the windows, it is absorbed by the interior surfaces, converting it into heat energy. This heat energy then radiates back into the car's interior, causing the temperature to rise. The windows of the car act as a barrier, preventing the heat from escaping, thus creating a warm environment inside the car. This effect is further amplified if the sun is shining directly on the car, as it will generate even more heat. Additionally, the color of the car's interior can also play a role, with darker colors absorbing more heat compared to lighter colors.