The interest rate is what you pay a car finance company for lending you their money. Essentially, unless you strike a 0% interest rate deal, you're not getting that money for free. Banks and other lenders do this because lending money is risky business, and they need some kind of safety net should things go south for their borrowers.
As a result, taking out a car loan ends up being more expensive in the long run. You just don't feel the effects immediately. This is why it's important to compare car loans and find ones with good deals on interest rates and terms.
