Do they serve any purpose, other than providing a charge for the pea-brained moron using them?

For whatever reason, we currently have several cars with these in our neighborhood. I get woken up at least once a night from them. My son, whose Asperger’s makes him really sensitive to loud noises, almost refuses to go outside. I’ve seen him completely shut down with anxiety when he’s out with the dogs and one blows by.

I’m generally pretty reasonable. The world is full of necessary inconveniences that you just learn to accept; because you know that while you don’t care for them, they serve a purpose to improve someone’s life. But what’s the purpose of that muffler on a 2005 Mazda that probably tops out at about 70 mph? (Also, I feel like chasing down the kid that lives up the street and saying, “Man, I bet that spoiler gets you an extra 3/4 of a mph at top speed. You must be almost fast enough to get a speeding ticket now! And the racing yellow goes nicely with the sun-damaged teal and primer gray of your Corolla. Race on, man!”)