Building on my earlier comment, if I had to guess, I'd say that it was a camera pursuit vehicle. The rails on the front are presumably to mount cameras onto.
You can see an alternate angle on the second take here (with a better view of the cameras mounted on the rear footplate):
and ifIf you zoom in a little, you can see (from earlier in the "making of" video) that there's a ball-shaped camera mounted insideinside the frame on the front.