Do all cars have a gas tank flap?

Not all cars have a gas tank flap. Some cars, particularly older models, may have a gas tank cap that is directly exposed without a flap. For instance, some classic cars or antique vehicles might have a gas cap easily visible on the exterior of the car, without a flap covering it.

Additionally, some newer vehicles may have a fuel door without a traditional flap. Instead, they might have a release mechanism that allows the fuel door to open electronically or using a button inside the car. In such cases, the gas tank opening is concealed behind a built-in panel that doesn't require a separate flap.