I've done some experimentation with this. We found that an honest, detailed description of stock sold more cars and saved us time. For example, displaying the full details of the service history (good or bad) didn't deter buyers and saved us a lot of time constantly calling people back with any details we'd omitted. There's the view that you need to get people through the door at all costs so you can sell them into the car when they're on site. We found that more often than not, customers didn't want to be persuaded that the car was actually OK even though it wasn't exactly what they were looking for.