You already know who won, but it's still amazing to watch.
This obviously won't be a fair race, but that's really not the point. Auto Express has pitted a Mercedes-Benz SLS AMG, one hell of a fast road car, up against one of Mercedes-Benz's Formula 1 cars in order to demonstrate just how much faster the F1 car really is than a road car. Of course, the difference between the cars would have been better shown on a twisty road course where the F1 car could have torn the SLS AMG a new one.
But the straight-line speed is still massively impressive, and you'll have to remind yourself that the SLS AMG really is a fast car, because it just doesn't look that way here.