None. You don't buy "from" Drivethedeal, you buy via Drivethedeal. Drivethedeal merely puts you onto a franchised dealer from which you can buy the car at a favourable price. By channelling a lot of customers through that dealer it enables the dealer to obtain volume discounts, which is how the reductions are made. The downside is that the dealer offering the discount may be miles away from where you live, so you don’t cultivate a relationship with your local dealer.