I was helping my girlfriend shop for a car and she liked the Rav4 because it offers AWD. We schedule an appointment with a salesperson to test drive an AWD Rav4 and we explicitly asked for the AWD version because we were not interested in the FWD version. When we arrive, I took one look at it and knew it was not AWD. The salesperson insisted that it was. We argued about this for a while until I finally told him, "look under the car, see that hole where the rear differential would be if it was AWD?" Not sure if it was an honest mistake or he was trying to pull a fast one on us.
On a separate occasion, when I was ordering my 335i for European Delivery, the salesperson insisted that I had to pay for MACO, training fees, etc but I knew better from doing my research on Bimmerfest and E90Post so I refused.