We've owned our car for two years and just found out that it has an Automatic Sound Levelizer.
Apparently the adults who drive the car suffer from an acute lack of curiosity that the newly-promoted-from-back-seat-to-front-seat child does not. That’s kind of sad, really, but the discovery has added a bit of auditory thrill to our acceleration/deceleration cycles.
Okay, maybe that's kind of sad, too.
In other news, our car also has intermittent windshield wipers and automatic windows, both of which we recognized right away.