as i'm sure most are aware there is a tax incentive to trade in your car at the dealership, if they offer you 50K for your car and the new car is 70K you pay HST on the 20K difference only, so basically in this scenerio (for ontario) 50K from the dealer would be equivalent to getting 54K privately..with this being said if you are willing to go through the hassle of private sale you will probably still come out on top
