We all have that dream car we want to buy. And, when we go to the car dealership, there are ample options for financing the purchase of that car with loans. But what is in the best interest of the loan provider may not be in the best interest of your financial security. A zero down payment can seem attractive, but it also means you will pay heavily on the interest of the car and in fees. What you don’t want to have are high monthly payments that take up a sizeable chunk of your income. This is why we have come up with the 30-5-10 thumb rule to help you evaluate your options and make a healthier financial decision.