Here is what will happen
you turn vehicle back in (say you owe 18K)
They sell it at auction (probably for 10K if you are lucky)
Then then will start harrasing you for the 8K
Either you pay it, or they will sue you
If they sue you you will get a judgement on your credit
Then they can take the money directly form your paychecks (usually 25% of net pay) until it is paid off.
Every step of this will destroy your credit score and make your auto enhanced credit score worthless for years to come.
Find a way to pay the loan unless you are literally having to make the choice between eating and the car payment (and by that I mean can't afford ramen noodles)
Too many people are walking away from cars right now because the payment is an inconveniece (not sure if this is your case or not). I have talked to people with a recent repo who just got back from vacation, are our spending $150 at the local sushi joint or whatever. It is not worth the long term costs to your credit and yoru finances.
Also, if you have credit cards, a repo would be more than enough reason for them to close your accounts, CLD you, or jack your interest rate (making a bad credit situation even worse.
