At least for Germany, it is pretty much impossible to really know the average price of a new car. This is mostly due to so called "Händlerzulassungen", which means the dealer will actually buy the car, register it for a day, and then sell it as officially "used". This is why at least in the official statistic, only 30% of all new cars in Germany are sold to private citizens. Dealers do this because they are then more flexible w.r.t. pricing, and also they often get bonuses for registering a certain amount of cars in a quarter.