sure, but then his car is worth less than the new one after 5 years and he may have put more money into it because its already been ridden hard and put away wet by who knows who.
having an incrementally larger payment now or adding a few months on to the loan for a new one may avoid taking a larger hit or earlier repairs and maintenance at trade in time.
if he goes new, he knows who has had the car already, no one.
if she is comfortable with new, she should go new. why give excess profit to the dealer on a used one and drive it off the lot and have auction value be 60% of what you paid for it? now you have a used car you cannot trade without taking a bath anytime soon if you get stuck.
its a FRICKING SIN to buy a used car and donate major profits to the dealer and his henchman, because he stole that car on trade, sold it for a tish less than what you deal for new if you simply negotiate, and is laughing the moment you get the keys. sure, its less than new, but you've also financed YOUR money to buy HIS PROFIT....buy new and he still rips you off for profit, but make a good deal on the new one and at least your money is going into the car, not the profit. New cars sell for a lot less profit than used, except hot models with big msrp's.
at least at off lease used places who buy their cars on the open market, they can priced them much less than the dealer CPO's and don't have as much dealer overhead from the megachains. if you can find something 1 year old or less with 10,000 miles and under for a big price difference than new, then its worth it. In my experience most CPO cars are overpriced compared to the ones you can buy at the nice professional executive lease return type of places, and its usually a big difference.