Those that do loans are much more likely to have negativity equity when trading in. Which is already proven with those who have terms longer than 4 years. This means on trading in, the borrower is looking at an increased car payment on top of the already higher average transaction price of $35,000. If you put money down, default on the loan and lose the car, you've quite literally given away money.
It's true the average loan is 7 years, but within the last few years there are 10 year (!) loans are available. This helps bring down an $800 payment. But that interest is gonna suck if you don't get a very low rate.
Those that pay off their loans tend to keep their cars for 10 to 12 years. Assuming the car doesn't catastrophically fail. Which anecdotally happened to our family. 1.6L Ford EcoBoost defect killed the engine 2 years after a 4 year loan was paid off.