That's the highest rate I have ever heard of. You need to refinance at a better rate...it will lower your payment drastically.
If the car is running well there is no need to trade. You obliviously are building or rebuilding your credit...more debt will not help you. Also, it does not make sense to increase your debt at high interest rates because you will be throwing away alot of money and surely have alot of negative equity in your car...most of the money you have paid so far is interest.
Good luck