A few months ago I discovered my 2004 Jeep Grand Cherokee had a feature I was totally unaware of, that being a warning that I had left a turn signal on too long. I had made a swooping left turn that did not turn off the turn signal and I didn't realize that. A mile later the Jeep makes the "beep-beep" sound that usually means a door or liftgate was not totally closed, then after a few seconds, I noticed the message "TURN SIGNAL ON" displayed in the Vehicle Information Center display. I wish I had the wits enough to take a picture of that to share, but it did lead me to look up other messages that could potentially also be displayed, as shown below.
I've either never had that feature on any of my other cars or this is the first time I've ever left a turn signal on that long (which is kind of hard to believe). In any case, it's a cool feature.