Need help asap in fixing my credit score

There's really no "quick fix". Without knowing what is on your credit report (ie chargeoffs, repos, collections, or delinquent accounts ; and how many accounts are being reported), I can't go much further.

I can tell you, if you have problem credit, then you won't be dealing with a bank or GMAC or Ford Motor Credit. You will more likely be dealing with a secondary finance company at a high rate. AND they don't like to do brand new cars, because they lose so much value once you drive them off the lot.

Secondary finance companies don't place all that much emphasis on the score itself. They look more at the actual tradelines, and other information like your income and employment history.

Another problem could be the amount you're requesting... what is the vehicle you're trying to purchase and how much are you putting down? Say the car you want black books at about $8000, then that is about as much as a finance company will loan out against it (maybe a little more depending on your credit). If the dealer wants $12000 for the car, you would need to come up with a $4k down payment.

To get rid of the things on your credit report, all you can really do is keep disputing it. But if they are valid debts, whoever is reporting them might keep validating them. Your only recourse would be if they are reporting inaccurate information.