[MRM]

You have nothing to regret. That's about what the car was worth, and you found someone who paid you what you thought was a fair price. You can torture yourself forever about whether you got the most for anything. The only thing that matters is if you got what you wanted from the sale. You did, now you have quite a bit of money that you can now use for something else you need more. You have nothing to feel badly about. You should be happy you had the car for as long as you did and look forward to getting a newr, faster, better one some day.