Function to move searches for non-post post-types / taxonomies to their respective archives.

gistfile1.aw

<?php
function yoast_change_template( $template ) {
	global $wp_query;
	if ( !isset($wp_query->query_vars['taxonomy']) )
		return $template;
		
	$taxonomy = get_taxonomy( $wp_query->query_vars['taxonomy'] );
	if ( is_search() && count( $taxonomy->object_type ) > 0 && !in_array( 'post', array_values($taxonomy->object_type) ) ) {
		set_query_var('post_type', $taxonomy->object_type[0]);
		$newtemplate = get_archive_template();
		if ( $newtemplate )
			$template = $newtemplate;
	}
	return $template;
}
add_filter('template_include','yoast_change_template',10,1);