Ok so about 5 months ago I went into a dealership to get a car and seen a mustang gt 2003 for 8k. I had bad credit at the time and no one in my family would help me by co signing. And my gf could not help out at the time because she was going to get her car first. They ended up doing an "in-house" financing and tried to get me with 24% apr but it's illegal in Texas to go over 23% ( I do believe) so they tagged me with 23% putting the car over 13k for 3 years. Ive been making payments all on time of $350. But it's not going on my credit. My question is now that my credit is not 580 anymore (it's 608) and now that I have a co signer who has a score of "678" should I hand in the keys and go someplace else ? Or ask them if it's possible to lower the apr now that my credit is better and I have a co signer!? The monthly cost is to high now that I've switched jobs. I can't pay insurance even anymore. I'm looking for some detailed help. Should I ask if they can lower the payments? And say if they don't lower it I'm turning in the keys? Because I can now get an 8k car for less than $250 a month!

The dealer who did your in-house financing is a scumbag "buy-here-pay-here" dealer who doesn't check credit, nor does he report credit. The amount you've already paid on the car has likely already paid the dealer what he had in the car. Because of the type of people he deals with, he actually expects cars to be returned and he doesn't report them to credit bureaus (because he doesn't work with them anyway). He simply puts the cars back on his lot and sells them again -- and again, and again.

Just be aware that since you signed a loan contract with this dealer, he may try to get ugly with you, and is within his legal right to do so. However, if you're already paid the money he needed for the car, he may simply ignore you.

Now, your improved score of 608 is still not that good and you'll have a hard time getting approved at a decent interest rate, if you can get approved at all. Your co-signer's score of 678 is better but still not ideal, but could get you approved at a much better rate than you're paying now.

PLEASE, PLEASE, PLEASE start learning about personal finance,

1. If you turn the car in, that is no different than you stop paying and the repossess it in the middle of the night. Your credit will be worse than 580.

2. You currently owe the loan company 23% interest, why would they reduce that "just because you asked"? They won't.

3. Please don't get a co-signer involved in your horrible finances. If this person wants to buy you a car, they can. But it's not fair to have a co-signer when there is about a 95% chance you are going to default (unless you learn about how money works).

4. You are free to find a company that many refinance your car. You need to make sure that there is not a downpayment and they are not extending the length of the loan.

You need to find a source of money to pay off the current loan. First read your current contract and make sure you can pay off the loan early without penalty. Then go with your co-signer to a bank/credit union etc and see if you can get a loan for the money you need to pay off the high interest loan.

then NEVER EVER take any loan for that interest rate ever again. Take a bus if you have to.

But it's not on my credit so how can a repo be reported

no, you don't turn in the keys. move the loan to a different lender if you can get a better APR and your current lender wont match it.

No, you should not "hand in the keys." That would be a voluntary repo and will kill your credit.