Update: Well, we bought a new-to-us CLS550. I guess we'll see how reliable this beast is over the next few years. It is a 2013 CLS550, white with tan leather interior. We looked at a 2014 E350 sedan but it wasn't nearly as nice as the CLS550.
Holy crap this thing is fast and comfortable. If you haven't driven one and get the chance I highly recommend it. It's a delightful car.
Oh, and we have 2 year unlimited mileage warranty through Mercedes-Benz and we added another 2 years onto that so we have 4 years of Mercedes factory warranty and our next 3 services are also free. So really it shouldn't cost us anything more than gas, tires and brakes.