Since we are pointing out errors in the name of digression:
That depends entirely on the interest rate you are paying for the car loan. If you are paying 0% interest then it is most certainly NOT more financially sound to pay cash.
Put another way: if I have $12,000 in my hand, and can choose buy a car outright or finance it at 0%, financing is the better option. I can take the ~$10k I have left (after down payment and such) and invest it, and any money I make is net profit over having paid cash for the car.
If you're going to nitpick, do it right.
Very very rare, will zero % financing come without giving something else up.
E.g. The ad in today's paper -- 0% financing OR cash $2000 rebate.
Unless you can make $2000 with your investment you would still be better off paying the less cash.