It's a car loan, what could possibly go wrong? You pay, they apply the payment. When you're done, they send the title. Should be pretty straightforward.
I wouldn't be concerned and you're not a sucker.
When my Subaru (financed through Chase) was paid off in one lump sum, Chase applied the balance to someone else' account. Then issued a big GFY when I called and tried to get it sorted out (after making two additional payments).
Carvana was very helpful in getting it paid off - obviously since Chase wouldn't do the lien release until it was paid off.
However, Chase was fighting it tooth and nail. Carvana provided the check information, confirmation that Chase cashed it and documentation that they paid off the correct account and Chase was just not having any of it. Eventually it did get sorted and I was refunded the correct amount.