modify API request using searchmodule_civicrm_apiWrappers
Solved. It's easier to append the results, that modify the original query, which is long, verbose and complex.

                public function toApiOutput($apiRequest, $result) {

                 //  $result format
                 //
                 //   [id] =&gt; 12345
                 //   [sort_name] =&gt; Last, First
                 //   [email] =&gt; first.last@gmail.com
                 //   [data] =&gt; Last, First :: first.last@gmail.com

                    $search_term = @$apiRequest['params']['name'];

                    if (strlen($search_term) &gt; 0) {

                        $additional_result = civicrm_api3('Contact', 'get', array(
                            'debug' =&gt; 1,
                            'sequential' =&gt; 1,
                            'return' =&gt; "sort_name, email",
                            'legal_name' =&gt; array('LIKE' =&gt; "%$search_term%"),
                        ));

                        // Increment count
                        $result['count'] += $additional_result['count'];

                        foreach ($additional_result['values'] as $key =&gt; $api_result) {

                            $result['values'][] = array(
                                'id' =&gt; $api_result['contact_id'],
                                'sort_name' =&gt; $api_result['sort_name'],
                                'email' =&gt; $api_result['email'],
                                'data' =&gt;  "[L] " . $api_result['sort_name'] . " :: " . $api_result['email']
                            );
                        }
                    }

                    return $result;

                }