public function add_hooks() {
			// Add an [invp_vehicle] form tag.
			add_action( 'wpcf7_init', array( $this, 'add_form_tags' ) );

			// Add special mail tags [invp_adf_timestamp] and [invp_adf_vehicle].
			add_filter( 'wpcf7_special_mail_tags', array( $this, 'add_mail_tags' ), 10, 4 );

			// Add a link to the vehicle before emails are sent.
			add_filter( 'wpcf7_mail_tag_replaced_invp_vehicle', array( $this, 'add_link' ), 10, 4 );
		}