Creditors view secured credit payment history very seriously. Anything like a car or home with late pays or repossession is a very serious mark on your credit report.
As you mentioned, the car can be repossessed, sold at auction for a fraction of what you owe, and then you may be billed for the remainder of the current balance on your auto loan. This is a pretty bad situation, for you are then paying on a car you do not own, have a rotten credit history that will make purchasing another car very difficult, and will still need transportation.
Even if a settlement company would take this on, debt settlement on the remainder of this loan may be much more difficult with potentially less than favorable settlement rates than regular unsecured credit.
My advice? Review your budget thoroughly, cut back on whatever you can, make those payments religiously on time, and even get a second job if you have to pay this off. This will be staying on your credit report for the next 7 years - are you sure what will be happening in your life for the next 7 years?
Will you risk needing a car loan, apt. rental or home purchase that may require a healthy credit score? Many folks think credit scores only affect the ability to get credit, but more and more landlords are hesitant to rent to potential tenants who have demonstrated a lack of good payment history. Some jobs also require that you demonstrate good financial management if you have a fiduciary responsibility as part of your job description.
Evaluate carefully, and good luck on improving your cash flow!
Arise, go forth, and Conquer! (Alfred Lord Tennyson)