Read the contract, mine didn't have it though (2020).

Prepayment penalties are rare outside of subprime/pay-and-go loans. When I worked at Ford Credit the max dealer markup on financing was 2%, and the dealer got their commission on the rate markup up front. Taking a crappy interest rate and prepaying is a sound negotiation tactic because it is the financing company that takes the hit.

Usually not. I've once financed a car just to get an additional rebate (few extra grands to finance through manufacturer) and paid it off next month.

I’ve done this. They asked me to leave the loan outstanding for two months and I ran the numbers on the interest that would accrue. They agreed to deduct that amount (several hundred dollars) from the purchase price.

Of course, this was pre-supply chain crunch, so now you’d probably be best off not saying you’d prepay and just doing it ASAP