In a hurry after we lost one car in an accident, I helped my daughter look for another one. It had several issues that violated the guidance of the Ultimate Used Car Buying Guide, but I bought it anyway since she needed it for school and work and we were running out of time.
Though I did look for oil leaks in the parking lot, this car turned out to have a very serious oil leak. Later I replaced the oil pan gasket to no avail. It was leaking from the main seal and would require major expense to fix.
My daughter was very disappointed in the vehicle, and my wife reminded me that I am not supposed to buy a car without her approval.
My advice is to not rush when you are shopping for an buying a car. Hurrying is when you make mistakes. In my case, it would have been better to rent a car for a week so as to not be in a hurry while shopping for one.
Post note: We finally got rid of the car after my daughter lost control on a rainy night and flipped it off the highway into a field. I had to pay the tow company to take it off my hands!