So are you saying i need to create a 3rd .java class and call it Car.java or NewCar.java?
It's normal to give classes a name that describes what they are modeling (representing). NewCar is not a sensible name unless the class can only represent new cars and not old cars which clearly isn't the case as your second car is 1 year old. Therefore, the class should probably be called Car.

If anyone can help me figure out HOW to do more than one car, because currently no matter what i do it only will add one car, then i would greatly appreciate the help!!
It's a bit hard to tell you how to do more than one car when you haven't shown us the code you are using at the moment.

Please post all of your code and remember to use CODE tags when posting the code.