Filtering with Slugs in Ember.js

I have two models - make and car. I have an application that shows all of the makes (manufacturers) and then another model that shows the models or cars. I have set up dynamic segment for slugs in the URL and I want to filter the makes by the slug which happens to be the niceName property.

route make.js

import Ember from 'ember';

export default Ember.Route.extend({

  model(params) {

    // find make by niceName using params.slug
    const niceName = params.slug;

    // find cars by make
    return this.store.filter('make', function(item) {
      return item.get('niceName') === niceName;
    }).then( function(result) {
      console.log( result.get('niceName')); // undefined
    });

  }

});

I have checked and it does correctly match those items with the same niceName. I can check the length and if I play with the value of niceName, it does change the length of what is returned.

The problem is that what is returned doesn't have any of the properties. If I attempt to show this in the view, it returns undefined as well.

What is filtering returning?