How are springs used in cars?

Answer 1

They are used to support the vehicles weight and allow the tire/suspension to move over bumps. They can be used to hold the trunk/hood open, like on old chevy pickups.

They are used to control the valve movement in the engine. Used in the seats to to give a comfortable ride. In belt tensioner to prevent the accessory belt from slipping. Certain hose clamps are spring clamps. Some headlight fixtures have springs to prevent shock from breaking the bulb. Most throttle bodies are still spring returned to closed. Any interior lids/trays have springs built in.