The ambulance and uhm.. doctors-car (????) are standard cars from the Nordschleife GmbH, that means they are always there when the track is open, they are usually parked behind the entrance, on your right from the webcam' point of view. Looking at the time of the shot it's 19:20, that's the time when they close the Nordschleife and the ambulance and doctors-car prepare to go home after a hard day work
I think the little car with the hood opened wanted to drive a lap and maybe bad luck striked and the car broked down even before they entered the ring. Although that would've been luck actually because once on the Nordschleife it's damn expensive when your car refuses to cooperate. €175,- for a tow.