Dealers Floating your money

Has anyone had their money floated by their Ferrari dealer? That is you pay off your car when you trade your Ferrari for another model ie 355 for a 360. The dealer is supposed to pay off your old car with the money you borrow for the newer one but instead uses your money for a few months or in other words is borrowing thousands of dollars for free and you may as I did end up with a credit problem when there are late payments by the dealer. This seems to be an increasing problem.