title: Bulk API efficiency
body: <p>I am currently working on a Rails (5 - Beta) app which is mainly a JSON API.</p>
  
  <hr>
  
  <p>I want to accept/process the following JSON:</p>
  
  <pre><code>{
     cars: [
       {name: "Car 1", hp: 120, model: "Model D"},
       {name: "Car 2", hp: 80, model: "Model A"}
     ]
  }
  </code></pre>
  
  <p>I am trying to take multiple instances of 'Car' with one call. (The idea is to avoid the HTTP overhead when multiple cars should be tranfered)
  With respects to Strong Parameters, how would I apply the <code>require</code> and <code>permit</code> methods here? I want to make sure that within the car instance only the specified attributes "survive".</p>
  
  <p>Thanks a lot!</p>