Maybe you could take advantage of that by putting a blue LED on your dashboard or rear-view mirror that blinks every few seconds when the car is off.
Speaking of, I'm surprised that there aren't more prank automotive devices. What if your car's horn went off semi-randomly twice a month, with a different horn sound each time? Or your turn signals made loud clicking noises that everyone could hear? Or your Bluetooth calls also broadcasted through the car alarm speaker on Wednesdays? There's plenty of room for innovation in the car alarm space.
Speaking of, I'm surprised that there aren't more prank automotive devices. What if your car's horn went off semi-randomly twice a month, with a different horn sound each time? Or your turn signals made loud clicking noises that everyone could hear? Or your Bluetooth calls also broadcasted through the car alarm speaker on Wednesdays? There's plenty of room for innovation in the car alarm space.