"What monthly payment are you comfortable with?" It sounds like a helpful question, but focusing on the monthly figure can hide how much you're really paying. A payment can be lowered simply by stretching the loan over more months, which can mean paying more interest overall.

Longer loans carry another risk. Cars typically lose value fastest early on, and with a long loan, you may owe more than the car is worth for a good stretch of time. That can become a problem if you need to sell it or if it's totaled in an accident.

Keep the conversation on the out-the-door price, which includes the vehicle price, taxes, title, registration and any dealer fees. Ask for that number in writing before discussing financing or trade-ins. Once you've agreed on it, you can figure out what loan length and down payment make sense for your budget. Choosing the shortest loan you can comfortably manage often keeps total costs lower.