WordPress Rewrite_rules_array Can not read own vars

I Use rewrite_rules_array Function In My Own Plugin. But I Have Same Problems.
Here’s My Code.

function addGoRewriteRule($rules){
$newrules =  array('go/([^/]+)$' => 'index.php?go=$matches[1]');
return $newrules + $rules;
}
function goInsertVars($Vars){
array_push($Vars,'go');
return $Vars;
}

But I Can not Read My go vars.
Somebody have a idea ?

Thanks For Help.