Thanks for the replies. I'm just digging into the blog and forum so still have a lot to learn, but found I do have some innate mustachian tendencies.
Breaking it down into two decisions:
1. Should I pay off the loan? -Yes. I maybe need to do a more thorough case study to decide how fast to pay it off because it seems this debt would fall under Investment Order priority 7 (
https://forum.mrmoneymustache.com/investor-alley/investment-order/), as the interest rate on the loan is less than 5% above the current 10-year Treasure note yield. I'm currently working on priority 3, fully funding my HSA.
2. Should I keep the car? -At this point I think this is also a 'Yes'. At the rate I currently drive I expect to get at least 14 more years out of the car. Since I already made the mistake of buying a new car and eating the initial depreciation, a quick search isn't turning up any cars that I'd get a similar lifespan from for less than I can sell the current car for. This supports the replies to run it into the ground. Again a more thorough search may change my mind.
40k is combined checking and savings, with the majority being online savings making ~2%. I'm a little more liquid than I'd like to be right now because I'm preparing for some window replacement and masonry repair for my house.
Looks like I have some homework to do, but would still welcome others' opinions.