Secretly, I want to purchase this car at the end of my lease. Of course I don't want the car company to know that. Anyway I have a "final inspection" coming up pretty soon, they asked me to clean it thoroughly inside and out. I'm thinking about keeping it quite dirty so the car company will deem it "unsellable" and end up willing to negotiate a lower price on the contract. And yes, you can usually negotiate it even after in writing.