First off, the answer depends on whether you are long or short on credit scoring. As we pay off loans etc, our score may dip a bit, but then picks up, and goes back up again.
For some people (like me at this moment) are looking for short term gains to get a better interest rate, qualify for a mortgage, refi, etc... and thus these short term drops hurt our goal of achieving one of the previous goals. So we will try and maximize the ideas we find on here to better our score in the short term.
For others (and hopefully all of us in the end), it is a marathon and not a short sprint. They do things now, that insure a payoff in the future (good scores and long history). And I would surmise paying off a loan (either early or on time) would be one of the goals of good financial responsibility.
Maybe this is a long and drawn out answer, but you have to decide what your goals are, short term and long term. Remember, if you fail to plan, you plan to fail.
IMHO, "IF" I had 24k sitting around, I would invest that money, as the car is a depreciating asset (ie it probably is not worth 24k right now, and won't be worth that ever), so there are better uses for that 24k...pay down your mortgage, buy some land...
