You don't pay interest upfront, so your question is a little confusing.
Not sure the kind of car you bought, but typically, as soon as you drive it off the lot, you just lost about 20% of the value.
You could trade in your current car, buy the Malibu LT2, and they would roll any negative equity into your new loan.
I wouldn't advise it because you will lose a killing.
After you roll the negative equity into the new vehicle, If you end up owing more than 20% of what the Malibu is worth, many lenders won't lend you the money...especially in this economy.
They will likely require an additional down payment.
