There will come a day when you will look back and wish you had been more mature about your transporation expenses. Your wasting money and it's quickly going to be in the five digit range. Worse yet, if anything upsets your cash flow, you could end up thousands (maybe tens of thousands) in the hole, and the car on the back of a repo truck.
Stop the insanity now. Pay off your car. Maintain it like you need it to last you another twenty years (because it can and you do) and when its paid off open a savings account and start making that payment to it like you bought another car. The only time you touch that money is if your car requires a major repair (over $1000) which you'll notice you then will have the cash for. Or else on the day your mechanic says that it's time for a new one, which again you'll hve cash for and will have learned the value of having a great mechanic look out for you and your car. About ten years from now, when your car has been paid off and your savings account has 20K+ in it, you'll realize just how much you really love your present car.