Modifying cars is something different for everyone. Some people frankly don't give a s*** if their car is mega fast. They don't race. They don't take their car to the track. They don't give a flying **** about getting a dyno or a professional tune. For some people, this hobby is all about building a perfect machine and pushing the envelope. For others, it's about simple modifications or changes to aesthetic details that make them happy or confident. If that useless whoosh noise is what makes you happy, and it isn't detrimental to your car, why the hell not?