What is the utility of your car?
Write down everything that you use it for in a three-month period. Sort by days used for that purpose. Throw away anything under, say, two days. You will most likely end up with: driving to work, groceries, maybe friends' houses, and 'sitting in the driveway'.
Then consider: How easily can you do all of those things without a car?
Costs to keep:
- Normal gas costs, maintenance, insurance, registration, and so on.
Costs to sell:
- The amount of money you "lose" from the sale is a weird sort of loss. You lose money in the sense that you get less than you put in, but you also gain money back.
- For any special purposes, consider the cost of renting.
- Chance you will really need a car in the next year, two years, five years; and the cost of buying another [used] car, including taxes, registration, and so on.
In other words, in your PLUS column, you will have the sale price less whatever fees you must pay, plus a monthly/annual "what I used to spend" value. In your MINUS column, you will have the cost of occasional rental + gas + fees, and the cost of buying another used car multiplied by the chance that you will have to buy another used car. In the EMOTIONAL MINUS column, you have the money you feel that you lost on the purchase and resale.
I suspect you will find that your biggest loss will be emotional, not financial.
Don't fall into the SUNK COST fallacy. Just because you already spent X doesn't mean you should continue to spend Y. If you spent X, it really means you should re-evaluate whether it was the right choice, and whether spending more is the right choice, or whether you should cut your losses and get out while you can. Also known as: don't throw the baby out with the bath water.