Your advice made sense years ago; these days it does not. 2-5 year old cars with low mileage don't cost much less than brand-new models these days, unless it's some unpopular model (and they're unpopular for a good reason).
My wife's 2 year old Honda Pilot with low mileage cost ~$12k less than new. That's a hunk of change. Now, the payments were a bit higher since you don't get 0% and you don't get to stretch it out over 7 years or whatever crazy long term that they have for new cars now, but you do still save significant chunks of change buying used. If we had gone even a couple of years older, the savings to be had were over 50% versus new for cars that are reliable, popular and have >100,000 miles likely left in them.
"Why should we subsidize intellectual curiosity?" -Ronald Reagan