You want the creditor to approve you for the low interest loan. This is another reason to have copies of your credit reports. This is your down payment. This question will tell you how much money you will have to come up with to make the car loan current and how desperate the creditor is. The creditor does not want to repossess the car, especially if the car is worth less than what the outstanding balance on the loan is.
Nobody wants to pay more for a car than what it is worth.
Bad for the creditor. Bad for the current owner. Two bad marks equal a good for the consumer with a bad credit file. You are more interested in the finance charges and reestablishing credit. Do not feel bad about taking over payments of a car that is worth less than what is owed on it.