Question about buying a car from a dealership?

Unfortunately, you are not able to enter into a legal contract until you are 18 years old. Even with a cosigner. But consider this a blessing. A 16 year old has no business going into debt for a car. It is a surefire means to financial problems that will last you well into adulthood. Go to the personal finance section and look at all of the people asking for help because they borrowed too much money and don't know how to pay it off. Don't become one of them.