promiseVersion.js

const Promise = require('bluebird');
const models = Promise.promisifyAll(require('./models'));

const {VehicleModel} = models;

function yourCode() {


    Promise.all(vehicles.map((ownedVehicle) => {
        return VehicleModel.findOneAsync({_id: ownedVehicle.vehicleId})
            .then((vehicle) => {
                return {
                    year: vehicle.year,
                    make: vehicle.make,
                    model: vehicle.model,
                };
            });
    })).then((vehicles) => {
        // I think this is output in the same order they went in as
        res.json(vehicles);
    });

}