The document discusses the best way to manufacture a car exhaust by describing the tube bending process. It introduces that an exhaust removes carbon monoxide from the engine and its main function. The tube bending process involves pulling the tube over a fixed mandrel to support the inner radius of the bend as the tube is formed into the bend die, preventing kinks or wrinkles. This process provides advantages as a simple, straightforward way to bend tubes for car exhausts without flattening or need for further finishing of the bent product.