I think it's more correct to say that it depends. If you have $XXk and need a car, is it better to pay cash for the car to save on interest, or is it better to have the cash in the bank and the opportunities it may qualify you for? I buy used cars, and my loans are still at 5.25 & 6%. Most places give better rates on new cars. I make maybe 4.5% on my savings account. Granted, that's before tax, but the spread of ~2.5% net really isn't much to have the chance to get into opportunities as they arise.
If you have the funds but are irresponsible and/or are absolutely certain you won't have any investment opportunities beyond risk-free rates, then pay cash.