title: How to use JsonConvert.SerializeObject with formatting to add brackets only around CSV values
body: <p>I have an object that, when converted to a JSON string using the <code>JsonConvert.SerializeObject</code> method, will look like this:</p>
  
  <pre><code>{"01":{"CompanyName":"Hertz","Cars":"Ford, BMW, Fiat"},
   "02":{"CompanyName":"Avis","Cars":"Dodge, Nash, Buick"}}
  </code></pre>
  
  <p>How can I use the <code>Formatting</code> parameter to make the result look like this:</p>
  
  <pre><code>{"01":{"CompanyName":"Hertz","Cars":["Ford", "BMW", "Fiat"]},
   "02":{"CompanyName":"Avis","Cars":["Dodge", "Nash", "Buick"]}}
  </code></pre>