Happy to explain. Sorry you had that experience and the good news (which we'll get to in a minute) is that there is probably an easy fix to get most of those points back.
First off, I am guessing that the car loan was your only loan and that (at the time you paid it off) the loan was mostly but not entirely paid off. If so, would you mind telling us the balance (just before the payoff) and also the original amount of the loan.
The bottom line is that FICO 8 really likes it when you have an open loan (one is all you need) that is mostly but not entirely paid off. Just before you paid it off, therefore, FICO was giving you a big score bonus for having this mostly paid off loan.
When you paid it off, however, you no longer had this mostly paid off loan, so you lost that scoring bonus.
The good news is that it is pretty easy to get that mostly paid off loan back. You can find out about it by reading the first 2-3 posts of this thread:
http://ficoforums.myfico.com/t5/Understanding-FICO-Scoring/Adding-an-installment-loan-the-Share-Secu...
