 If this were just any door, and this were just any ignition, connected to just any transmission, in just any vehicle, then perhaps it would be okay to buy it from just anyone. But this is not just any car. It's a certified pre-owned Mercedes-Benz. Every detail has been inspected and road tested by highly skilled Mercedes-Benz technicians, and it's all backed by an unlimited mileage warranty for up to five years, which makes the decision of where to buy one simple. Your authorized Mercedes-Benz dealer.