Andy doesn't quite understand how car loans work. His answer is wrong.
Interest (APR) is added every month to your outstanding loan balance and makes up part of your monthly payment. As time goes on, and your loan balance decreases, the amount of interest in each monthly payment is less.
Interest is not charged or added to your loan ahead of time. It's only added each month. So, as an example, if you paid off your loan in only 3 months, you would have paid only 2 months of interest — not very much at all.
Now, most loan contracts show you your loan amount AND the total amount you will have paid, including interest, by the time you have paid off the loan.
They add up the total amount you're being loaned, the APR your paying and divide it by the months you're financing the car for. That will determine your monthly payment. Don't forget you will need full coverage insurance for the life of the loan. I've seen people buy cars only to find out they really can't afford to insure them. Don't become a slave to a car payment.
The APR should be listed on the loan agreement. You borrow how much money you need. That is listed on the loan agreement. You wind up paying the loan amount (listed on loan agreement) plus the interest that you incurred with the loan.
Normally, the interest is deducted from your payment first, then what's left over is applied to the balance owed. If you pay off the loan early, you save interest.
HOWEVER, there's what's called "add-on" interest. They add the full interest to the balance owed and you pay 100% of the interest whether you pay it off early or over the full length of the loan term. Avoid these loans. They are usually done by independent car dealerships and Buy Here, Pay Here dealerships. This is also done with "0% financing from brand name dealerships. They simply add the financing cost to the price of the car.
it is not included in the loan amount. they use the loan amount and the APR to calculate how much per month to charge you in interest.
You have a fundamental cluelessness.