Speaking to a few people who have brought brand new cars and it seems to vary the mileage there "Brand new cars" come with. They appear to be anything up top a few hundred miles.
Personally If I was buying a brand new come car I would wont it to come with single digit mileage on it.
My friend got his new Astra from the dealer and It had 480 miles on the clock. I said he should question this but he just said they drove it from another branch.