myApp
 controllers
  cars.js
 models
  car.js
 app.js
 package.json

var express         = require('express');
var bodyParser      = require('body-parser');
var mongoose        = require('mongoose');
var methodOverride  = require("method-override");
var app             = express();
...

**var models = require('./models/car')(app, mongoose);**
**var CarCtrl = require('./controllers/cars');**