How soon can you trade in a new car after buy it?

There are no restrictions on how soon you can trade in a new car after buying it. You can trade it in the same day you buy it if you choose. However, it is important to keep in mind that trading in a car too soon can result in losing money. When you trade in a car, the dealer will give you a value for your car and then apply that value to the down payment of the new car. The value of your car will depreciate the moment you drive it off the lot, so if you trade it in too soon, you will not get as much for it as you would if you waited.