The hand-over of a car is basically a nice conclusion of the purchase process. The car is polished, the paperwork is handled by the dealer, and the only thing on your mind is to drive off. However, it is recommended to go through the agreement you made with the seller one more time. Make sure that all the promises are honoured. It is always easier to get things done while you still have your money in your pocket.
The engine is the most expensive part of a car and probably the hardest to judge. A quick peek in the engine bay is interesting, but what can actually be seen here? Under the bonnet you can find clues that point to the weak and worn out parts of the engine. A weak part may require maintenance, but can also mean very expensive repairs, in which case it is advisable not to buy the car.