Great info. Whether buying from a used car dealer or a private seller, I always take with me a checklist I have that is about 3 pages long. I spend 30-45 minutes combing over every detail of the car - this not only lets you see every aspect of the car, but also can intimidate the seller and let them know that you really know what you're looking at. Ask if they'll let you do a compression test (if you have a gauge). Ask if you can pull the valve cover. If you put the pressure on them like this and they really want to sell the car, they'll let you and you can use this to your advantage.