It depends on the model and generation, 4-5 years difference can mean that the two cars just have the same name, but not much is similar where it counts. I think my general rule is to buy a used or new car made in its last couple years of years of production where hopefully all the basic improvements for quality and reliability have been done. I also look at the owners location and if its been mostly rural miles, I don't worry as much about higher mileage.