Customer Area menu hack: Keep submenu open when editing the CPT.

customer-area-menu.php

<?php
/* 
Plugin Name: Customer Area menu hack
Description: Keep submenu open when editing the CPT. 
To be used with the plugin http://wordpress.org/extend/plugins/customer-area/
*/

add_action( "admin_footer-post.php", 'b5f_highlight_menu_item' );

function b5f_highlight_menu_item()
{
	// Not our post type, bail out
	global $typenow;
	if( !in_array( $typenow, array( 'cuar_private_file', 'cuar_private_page' ) ) )
		return;
	?>
	<script type="text/javascript">
		jQuery(document).ready( function($) 
		{
			$('#toplevel_page_customer-area')
					.removeClass('wp-not-current-submenu')
					.addClass('wp-has-current-submenu wp-menu-open menu-top');             
			$('#toplevel_page_customer-area a[href="admin.php?page=customer-area"]:first')
					.removeClass('wp-not-current-submenu')
					.addClass('wp-has-current-submenu wp-menu-open'); 
					
			if( !$('a[href="edit.php?post_type=<?php echo $typenow; ?>"]').parent().hasClass('current') )
				$('a[href="edit.php?post_type=<?php echo $typenow; ?>"]').parent().addClass('current');
		});     
	</script>
	<?php
}