Engine Block Heater Warning

We purchased a 2013 Fusion about a year ago and absolutely love it! We were told that since we live in Wisconsin it came equipped with an engine block heater. It's a great feature! The issue is, both my wife and I have driven off with the extension cord still attached to the car! It sounds stupid but on both occasions we walked past the front of the car with our hands full with a 2 year old and all the necessities required to get her to day care thinking "Oh, I have to remember to unplug the car". By the time we load everything into the car and get her strapped into the car seat we forgot and drove off. It ended up pulling the plug out of the front bumper. Thankfully there was no damage and the dealership was able to snap it back into place. It would be great if there was some sort of dashboard warning (and a sound) to let you know it is still plugged in if you put the car in gear while it is still plugged in. Thanks again for the great vehicle!