On 15 September last year, Markus Zahn parked his bright orange McLaren Spider in a car park bordering a paddock in Vogelsberg, a district in Hesse state.
A donkey called Vitus then chomped on the back of his car, he says.
The police suggest Vitus may have confused the car for a carrot.
But the donkey's owner is disputing the claim for €6,000 (£5,260; $7,050) to pay for the damage.
He says Vitus may not have been the culprit and that Mr Zahn should not have parked his car - reportedly worth €300,000 - next to the paddock.
The civil court in Giessen will rule on Thursday in a case that has received national media attention.
