Would you though? Like it could be ready for collection and the new owner can't pick it up etc. Still no reason for others not to see it. When I bought my polo the salesman took me in to see one they had in the colour I wanted. Helped me make a decision and I'm sure the buyer never knew or caredI know. But if I had paid for a car, and then found out random people had been invited to go over it in the showroom before I got the keys myself? I know I'd be a bit miffed to be honest.