Modify code to auto complete on taxonomies instead of title - autocomplete

Question

I've been trying for hours to modify this plugin to work with custom taxonomies instead of post titles and/or post content
http://wordpress.org/extend/plugins/kau-boys-autocompleter/
Added the code / part of the plugin where I think the modification should be done. I could post some stuff I tried but I think it would just confuse people, I don't think I ever came close. Normally I can modify code perfectly but just can't seem to find it. I've tried this method posted here.
http://wordpress.org/support/topic/autocomplete-taxonomy-in-stead-of-title-or-content
But it doesn't work. I've tried searching for possible solutions around his suggestion but I'm starting to think his suggestion isn't even close to fixing it.
if(WP_DEBUG){
error_reporting(E_ALL);
} else {
error_reporting(0);
}
header('Content-Type: text/html; charset=utf-8');
// remove the filter functions from relevanssi
if(function_exists('relevanssi_kill')) remove_filter('posts_where', 'relevanssi_kill');
if(function_exists('relevanssi_query')) remove_filter('the_posts', 'relevanssi_query');
if(function_exists('relevanssi_kill')) remove_filter('post_limits', 'relevanssi_getLimit');
$choices = get_option('kau-boys_autocompleter_choices');
$framework = get_option('kau-boys_autocompleter_framework');
$encoding = get_option('kau-boys_autocompleter_encoding');
$searchfields = get_option('kau-boys_autocompleter_searchfields');
$resultfields = get_option('kau-boys_autocompleter_resultfields');
$titlelength = get_option('kau-boys_autocompleter_titlelength');
$contentlength = get_option('kau-boys_autocompleter_contentlength');
if(empty($choices)) $choices = 10;
if(empty($framework)) $framework = 'jQuery';
if(empty($encoding)) $encoding = 'UTF-8';
if(empty($searchfields)) $searchfields = 'both';
if(empty($resultfields)) $resultfields = 'both';
if(empty($titlelength)) $titlelength = 50;
if(empty($contentlength)) $contentlength = 120;
mb_internal_encoding($encoding);
mb_regex_encoding($encoding);
$words = '%'.$_REQUEST['q'].'%';
switch($searchfields){
case 'post_title' :
$where = 'post_title LIKE "'.$words.'"';
break;
case 'post_content' :
$where = 'post_content LIKE "'.$words.'"';
default :
$where = 'post_title LIKE "'.$words.'" OR post_content LIKE "'.$words.'"';
}
$wp_query = new WP_Query();
$wp_query->query(array(
's' => $_REQUEST['q'],
'showposts' => $choices,
'post_status' => 'publish'
));
$posts = $wp_query->posts;
$results = array();
foreach ($posts as $key => $post){
setup_postdata($post);
$title = strip_tags(html_entity_decode(get_the_title($post->ID), ENT_NOQUOTES, 'UTF-8'));
$content = strip_tags(strip_shortcodes(html_entity_decode(get_the_content($post->ID), ENT_NOQUOTES, 'UTF-8')));
if(mb_strpos(mb_strtolower(($searchfields == 'post_title')? $title : (($searchfields == 'post_content')? $content : $title.$content)), mb_strtolower($_REQUEST['q'])) !== false){
$results[] = array(
'url' => get_permalink($post->ID),
'title' => highlightSearchString(strtruncate($title, $titlelength, true), $_REQUEST['q']),
'content' => (($resultfields == 'both')? highlightSearchString(strtruncate($content, $contentlength, false, '[...]', $_REQUEST['q']), $_REQUEST['q']) : '')
);
}
}
printResults($results, $framework);
function highlightSearchString($value, $searchString){
if((version_compare(phpversion(), '5.0') < 0) && (strtolower(mb_internal_encoding()) == 'utf-8')){
$value = utf8_encode(html_entity_decode(utf8_decode($value)));
}
$regex_chars = '\.+?(){}[]^$';
for ($i=0; $i<mb_strlen($regex_chars); $i++) {
$char = mb_substr($regex_chars, $i, 1);
$searchString = str_replace($char, '\\'.$char, $searchString);
}
$searchString = '(.*)('.$searchString.')(.*)';
return mb_eregi_replace($searchString, '\1<span class="ac_match">\2</span>\3', $value);
}
function strtruncate($str, $length = 50, $cutWord = false, $suffix = '...', $needle = ''){
$str = trim($str);
if((version_compare(phpversion(), '5.0') < 0) && (strtolower(mb_internal_encoding()) == 'utf-8')){
$str = utf8_encode(html_entity_decode(utf8_decode($str)));
}else{
$str = html_entity_decode($str, ENT_NOQUOTES, mb_internal_encoding());
}
if(mb_strlen($str)>$length){
if(!empty($needle) && mb_strpos(mb_strtolower($str), mb_strtolower($needle)) > 0){
$pos = mb_strpos(mb_strtolower($str), mb_strtolower($needle)) + (mb_strlen($needle) / 2);
$startToShort = ($pos - ($length / 2)) < 0;
$endToShort = ($pos + ($length / 2)) > mb_strlen($str);
// build the prefix and suffix
$prefix = $suffix;
if($startToShort){
$prefix = '';
}
if($endToShort){
$suffix = '';
}
// set maximum length
$length = $length - mb_strlen($prefix) - mb_strlen($suffix);
// get the start
if($startToShort){
$start = 0;
} elseif($endToShort){
$start = mb_strlen($str) - $length;
} else {
$start = $pos - ($length / 2);
}
// shorten the string
$string = mb_substr($str, $start, $length);
if($cutWord){
return $prefix.$string.$suffix;
} else {
$firstWhitespace = ($startToShort)? 0 : mb_strpos($string, ' ');
$lastWhitespace =($endToShort)? mb_strlen($string) : mb_strrpos($string, ' ');
return $prefix.' '.(!empty($lastWhitespace)? mb_substr($string, $firstWhitespace, ($lastWhitespace - $firstWhitespace)) : $string).' '.$suffix;
}
} else {
$string = mb_substr($str, 0, $length - mb_strlen($suffix));
return (($cutWord) ? $string : mb_substr($string, 0, mb_strrpos($string, ' ')).' ').$suffix;
}
} else {
return $str;
}
}
function printResults($results, $framework){
if($framework == 'scriptaculous'){
echo '<ul>';
foreach($results as $result){
echo ' <li>
<a href="'.$result['url'].'">
<span class="title">'.$result['title'].'</span>
<span style="display: block;">'.$result['content'].'</span>
</a>
</li>';
}
echo '</ul>';
} else {
foreach($results as $result){
echo str_replace(array("\n", "\r", '|'), array(' ',' ', '|'), '<span class="title">'.$result['title'].'</span><p>'.$result['content'].'</p>')
.'|'
.str_replace(array("\n", "\r", '|'), array(' ',' ', '|'), $result['url'])
."\n";
}
}
}