Here's the thing... It's a "driveway" and it's unreasonable to expect no wear or discoloration on untreated concrete (ask any concrete company if that is reason

Here's the thing... It's a "driveway" and it's unreasonable to expect no wear or discoloration on untreated concrete (ask any concrete company if that is reasonable and they will tell you "No"). If he was concerned about that he should have moved his car to a place on his property where this could not occur. If he did not tell you that was a concern before you started, and especially if he parked the car there and told you to clean it there, I don't see how he has a case. I would check to see if he's done this kind of thing before (and I'd be surprised if he hasn't) because that is evidence that he purposely set you up. If he has bring those records to court with you there's a good chance a judge would toss his case.