[Thaide]

A little complex and could take a little work but:

Go to a clothes store, such as Debenhams (english ok, some sort of department store with mannekins). Go to the customer service desk and ask if they have any old mannekins they dont need. Trust me, i've had a friend who's done this b4. You'd need two.

Dress one up as one of the victims and one as Konrad. Do a couple of shots of the two heroes fighting and eventually lying in the road wrestling. End the action with Conrad straddling the victim. Have Conrad say some phrase like "Revenge or something". While the fighting is going on have shots of a car in the distance, maybe the headlights etc. Make the victim notice the car and push Conrad up into the headlights. This is when the car should be fairly near and the lights are visible on the people.
HAve the victim say an one line like "Chew on this". And a look of shock on the zombies face. Then have the car run over the mannekins making sure the one of the victim goes untouched and the zombie goes flying. If the car is fast enough it should send the zombie flying or even better break it in half. Add gore effects afterwards with the actor covered in blood or something. And have the other zombies die suddenly also. Perhaps whilst fighting the other two victims.

Bit long winded but should work.