I found Carsense online by looking for cars at cars.com. While I was actually in the market for a car, I didn't think I was quite ready to purchase (I was still waiting for insurance to finalize everything after an accident that had totaled my previous car). I inquired about a Ford Focus, after which I received an email from Kyle acknowledging that it was still available, and inquiring about whether I'd be interested in a Ford Fusion that had just been reduced in price.
Everything was completed within an hour while I sat at my desk, I went a couple of hours later, signed off, and picked up my new-for-me, certified pre-owned vehicle. Painless. And the warranties that they offer are by far the best I've ever seen on used vehicles.
I was very impressed with the whole experience, and have already recommended them to friends and family (one of whom has already made a purchase!). I can't thank them enough for making this the best car buying experience I've ever had.