While fortunately avoiding killing anyone.
The experience of failing to dress properly for the weather can be an absolutely miserable experience, just ask Napoleon... or Hitler. It's bad enough when the mistake is due to your own failure to check weather reports, but when you have checked and the reports were wrong, that's when you really get mad. So Toyota Europe found an interesting way of holding weather forecasters responsible when they get it wrong, by placing them in an Aygo with a sunroof that won't close if they predicted sun.
It's mostly a bit of fairly harmless fun, although sitting in a pile of snow wearing a polo shirt probably would have caused hypothermia.