I used to sell cars in a previous life and would seriously recommend against 5 Year finance. While it's great for keeping the monthly payments down you'll be in negative equity on the car for at least 3 years. As for new, slightly used and used I'd say it would depend on the car.
Some of the demonstrators I used to drive where thrashed more times than I can remember If it's Japanese it can normally take it, French/Spanish less so!
Good luck, hope you find a good'un