Many consumers agree to unfavorable loan terms when financing used vehicles because they are, as you say, "desperate." In our society, many people are unable to carry out their day-to-day activities, such as going to work and taking their children to school, without owning a vehicle. As a result, consumers in a financial bind are often forced to pay high prices and interest rates to finance a car, because without it their financial situation would be even worse.
Your description indicates that you found yourself in a similar situation when you agreed to a 19% interest rate on your auto loan. Many used car dealers make huge profits by financing cars for people with credit problems, convincing buyers to finance over-priced vehicles at bloated interest rates.
The good news is that you may be able to refinance your current auto loan at a lower rate, potentially saving you thousands of dollars over the life of the loan. Based on your current credit score as stated in your question, it sounds like your financial situation has taken a turn for the better since you first financed your vehicle. A 670 credit score places you in the "moderate" credit score range (you are not "prime" but you aren't really "sub-prime" either, lenders would call you "Alt-A").
A 670 score is not a particularly bad score, and it should be good enough to allow you to qualify for an interest rate a lot lower than 19%. An auto loan refinance basically works the same as a home loan refinance — your new lender will pay off your old auto loan, leaving you with a new loan with the same balance as your old loan, but with a lower interest rate. To find out more about auto loan refinancing, read the article at Auto Refinance Advice
The Bills.com Savings Center, available at the top of most pages on Bills.com, is a good place to start your search for a lender willing to refinance your auto loan. Given your credit score and your current interest rate, I am hopeful that you will be able to find a lender able to help you lower the interest on your current auto loan.
I hope this information helps you Find. Learn & Save.