Gone to buy a car from a well known dealer that was advertised on autotrader and their own website for a price. However, on going to see the car in person, we noticed the price in the window is £200 lower. They have said this is a genuine mistake as can be seen by the fact the online prices match. I have said I understand mistakes can happen, however we would expect them to honour the lower price in the car window as this should have been checked before we came to test drive and look around. (It wasn't just a price in the window, it was a full print-out of the car specification & number plate etc with the price at the top). AIBU?