Auto finance is what I do for a living and what will happen is the lender will sell your vehicle at auction for much less then it's worth and then come after you for the difference plus all fees for towing, storage, reconditioning, auction, interest, lawyers and anything else they can think of.
This will amount to several thousand dollars and if you do not pay they can take you to court, win a judgment and at that point they can attach bank accounts, garnish wages (if your State allows it) and file liens on any other real property you may own like cars, boats, land and homes.
All of this will show on your credit for the next 7-years making it very hard to get any other types of loans without making massive down payments, paying huge fees and State maximum interest rates.
You would be much better off to either sell the vehicle yourself and pay any difference or refinance for a longer term so you can lower your payments. Either way you can salvage your credit.