Running into a camouflaged prototype or mule out on the street is a rare and special occasion even if it turns out to be some boring family sedan or crossover. But running into a prototype for the upcoming BMW M4? Well, that's downright magical.

Over at BMW forum Bimmerpost, user kyleshim got so caught up in the magic of encountering an M4 in development, he chased after it on foot in freezing-ass Jersey City while carrying a video camera. I certainly can't blame him. That's an awesome get.

The other thing we can take away from this is that if the production model stays close to this, the M4's exhaust note will sound ludicrously mean.