yii - Yii Cgridview how to render in view 2 or more values from the same table in 1 column

Question

I have a Cgridview that has multiple columns. I would like to merge and render the values of 3 columns in 1 column.

 <?php $this->widget('zii.widgets.grid.CGridView', array(
'id'=>'policy-grid',
'dataProvider'=>$dataProvider,
'filter'=>$dataProvider->model,

'selectableRows'   => 1, // you can select only 1 row!!
'selectionChanged'=>'function(id){ var objectId = $.fn.yiiGridView.getSelection(id); 
 if (isNaN(objectId) || objectId == ""){return;} location.href = 
"'.$this->createUrl('policy/view').'&id="+$.fn.yiiGridView.getSelection(id);}',
'htmlOptions'=>array('class'=>'grid-view grid_pointer',),

 'columns'=>array(

  array(
       'name'        => 'compliance',
     'type'        => 'html',
     'value'       => '$data->status == "ACTIVE" ? (CHtml::image($data->compliance == 
    "SUFFICIENT" ? "images/policy_sufficient.png" : "images/policy_insufficient.png")) 
    : "N/A" ',
     'filter'      => VFFormUtil::getFilter(VFFormUtil::POLICY_COMPLIANCE),
     'htmlOptions' => array('style'=>'text-align: center'),
  ),

  array(
       'name'        => 'status',
     'filter'      => VFFormUtil::getFilter(VFFormUtil::ACTIVE_INACTIVE),
     'htmlOptions' => array('style'=>'text-align: center'),
  ),

  array(          

      'name'        => 'coverage_left',
      'htmlOptions' => array('style'=>'text-align: center'),
  ),

  array(
      'name' => 'model_year', 
      'htmlOptions' => array('style'=>'text-align: center'), 
  ),
  'make',
  'model',

How would I combine 'model_year','make' and 'model', into 1 column in the views?