My 2013 E350 MB monitors driver alertness through steering, brake and throttle input alone. And it's surprisingly good, facial recognition is not required. The

My 2013 E350 MB monitors driver alertness through steering, brake and throttle input alone. And it's surprisingly good, facial recognition is not required. The only time it gets triggered is when I'm doing late night or very early morning driving, when you'd expect deteriorated attention - I don't feel drowsy so it's beeping is quite annoying but that's the whole point...