Neither did I.
I don't remember who said this (could've been Twain or Will Rogers) but some wise person said, "the older I get, the smarter my parents were."
So you got that going for you.
That said, ask him what he would do if he had an extra 10,000 dollars in his pocket.
Then show him how financing a car is like throwing away 10,000 dollars over the life of the loan.
Show him that even though the list price on the car is X (say 20,000 dollars), by the time he's done paying for it, he will have spent Y (30,000 dollars at least).
A 10,000 dollar difference. At least. Obviously it depends on the "price" of the car.
I was on my own and enlisted at 17.
I listened to my Dad and took his boring advice. At one point I wanted a Corvette . . . used from a friend, he said you don’t need a Corvette. Then I almost bought a Camaro Z-28 new . . . and beautiful . . . he said you don’t need that and instead I bought a “company car” from where he worked that came off lease for 1500.00 . . . low miles a Chevy Malibu . . . drove it for 3 years and sold it for 1200.00. So not bad. But I do wish I’d have bought either the Corvette or Camaro . . . this was in like 1980.
>>Then show him how financing a car is like throwing away 10,000 dollars over the life of the loan.
Have you looked at interest rates lately? You can get new cars at 1.75%. That’s less than $1000 in interest over a 60 month loan.