data.cars['Nissan'][0].model // Sentra
data.cars['Nissan'][1].model // Maxima
data.cars['Nissan'][2].doors // 2
for (var make in data.cars) {
for (var i = 0; i < data.cars[make].length; i++) {
var model = data.cars[make][i].model;
var doors = data.cars[make][i].doors;
alert(make + ', ' + model + ', ' + doors);
}
}