What can cause a car to smoke from the inside?

A car may smoke from the inside due to several reasons, including overheating components, electrical shorts, or burning oil. A malfunctioning heater core can also leak coolant, causing steam or smoke to enter the cabin. Additionally, if debris or food is trapped in the heating system, it can burn when heated, producing smoke. It's important to address any smoke issues promptly to prevent further damage or hazards.