It's the sun reflecting off of the hood. Super-tiny, super-bright lights going into tiny lenses sometimes create little flares on the opposite side of the image.
You can tell because they appear and disappear at the same time the hood-reflections do. At one point there are two reflections of the sun and it makes two flares.
I suspect they are dancing around like that because the optical image stabilization smooths out the car video but not the flare itself. So you get the reverse: your hand's motion mapped onto the flare.
EDIT: I took a sample shot with my iPhone 6S in a very obvious way. You can clearly see here what's going on; the extreme light bounces around inside the lens and lets you see everything. Essentially you're getting an image of your own camera. When it's the sun, though, it's so bright it doesn't come out this clear. It just looks like a white dot.