Here is one source: https://www.nerdwallet.com/article/loans/auto-loans/average-monthly-car-payment
A Google search will turn up more results with slightly different results but not wildly different.
The Tesla figures are from the Tesla website. Are they real? Yeah, I think so. All I'd need to do is click buy and my CC would be billed for the order fee and the car would mine in a couple months.
That site I quoted for a new car, also has figures for the average used car and it's more than half of what I quoted. Could a good mechanic get by for less? Probably. Average car transaction price has gone up recently and the average buyer has an expected price target that has also risen. With that figure in mind, the average buyer will shop to get a car as close to the target as they can and thus spend more on a used car than they would have spent five years ago.