So if I you're an engaged user, thinking about your score, and the guy in front of you slams on the brakes, your score gets a negative hit even though you did the right thing and braked hard enough to keep from rear-ending the person. Same is true if someone cuts you off, pulls out unexpectedly, or otherwise drives erratically or irresponsibily. In fairness, you can turn those three features off, but beyond an emergency crash phone call, I see little use for this device other than checking and clearing check engine codes. And yes, I've tried to use this with IF (formerly IFTTT) and I have a Nest and have tried using it with that (the constant text messages were annoying so I disconnected my Automatic from the Nest - the Nest on the other hand is AMAZING, I've had it two years and I LOVE it).