* Buy a car because you can "afford the payments." Ever wonder why car dealers advertise the cost of a car in monthly payments? Writing $32,000 in window paint isn’t quite as catchy as $379 a month (for 60 months with a balloon payment at the end).
    * Drive like an idiot. It's hard to save money on car insurance when you are collecting traffic tickets right and left. Not to mention the hit you'll take on gas mileage.
    * Refuse to buy a used car because you don’t want someone else's problem. This tired saying keeps coming up in discussions on used cars. A car transforms from new to used the second it leaves the car lot. A well-maintained, previously owned car can save you thousands of dollars over a new model.
    * Buy a new car because it gets better gas mileage. In most cases, you'd have to drive thousands and thousands of miles to break even. Buy a car for better gas mileage only if you already planned to buy another car.
    * Don’t shop for car insurance. No, seriously, take the first offer you get. That will save you tons of money.

  * Co-sign a car loan for your best friend. I no longer borrow money to buy cars. And I especially wouldn’t borrow money to buy someone else a car. As a co-signer, you are on the hook if your friend defaults. And if he needs a co-signer, there's a good chance he will.
    * Give up credit virginity for a free T-shirt. When I was in college, I signed up for a Discover card because the company was giving away free T-shirts. Dumb. My running joke is the T-shirt probably cost me $500 in interest over the next few years.
    * Borrow money from your parents. Not only does it change the relationship between parents and kids, it also makes it tough to declare financial independence when you constantly have to turn to the Bank of Mom and Dad.
    * Pay off a credit card with a credit card, without retiring one of them. A balance transfer from a high-interest credit card to a low-interest one makes sense in the short run -- unless you keep using both cards.