Editable add another message

Just wondering if it would be possible to allow the 'Add another %type' message to be editable per content type? Even giving it theme possibilities would be helpful. I have currently patched the module file itself to check for a certain content type to display different text after each node of that type has been saved.

        $node_type = node_get_types('name', $node->type);
        if ($node_type == 'Carpool') {
        $_addanother_message = t('Add a <a href="@typeurl">%type</a> post for your return trip.', array(
          '@typeurl' => url('node/add/'. str_replace('_', '-', $node->type)),
          '%type' => node_get_types('name', $node) // would return value Carpool
          ));
        }
        else {
        $_addanother_message = t('Add another <a href="@typeurl">%type</a>.', array(
          '@typeurl' => url('node/add/'. str_replace('_', '-', $node->type)),
          '%type' => node_get_types('name', $node)
          ));
        }

In this situation if they wanted to have multiple postings they would choose a repeating date value associated with this content type. So I felt it nicer if the text was more descriptive about the next tasks available to the user.