With a little help from David Bussell:
Int. Car
A man is driving a car. A woman is in the passenger seat. Something thumps against the windscreen and over the top of the car.
Woman: What the FUCK was that?
Man: A fly.
The man turns his windscreen wipers on as blood pours down the windscreen.
Woman: It was a man!
Man: Don't be daft.
Woman: It was 6 foot tall!
Man: Probably one of those European flies.
Another thump against the windscreen.
Man: Bloody things!
The man turns his windscreen wipers on again.
Woman: STOP THE CAR!
Man: It's just a couple of flies!
A loud thump is heard. The car rolls over something.
Woman: STOP THE FUCKING CAR!
Man: (SIGHS)
He puts his foot to the pedal. They screech to a halt.
EXT. HIGH STREET - CONTINUOUS
A swathe of destruction has been cut through a pedestrianised area. Shoppers gasp and weep. The corpse of a man lies right behind the car. The man examines the corpse.
Man: There must be a nest round here.
ENDS