I am not a debt absolutist, but debt on a car is just not smart and means you are buying too much car. Car purchases are the financial crux of the middle class. You want as low a % of your world tied up in cars as possible. Right now, the value of my wife and my cars (no kids) are 8% of our annual income.
I have friends that bought $35,000 trucks and make about $35,000 then wonder how we could afford to buy a home when they can't. They have a whole year's salary going backwards in value, on loan, while I drive "junky" cars that equal 8% of my salary going backwards in value.