Toyota 2012 Prius Owner's Manual page 334

2-3. Operating the lights and windshield wipers
NOTICE
■
When the rear window is dry
Do not use the wiper, as it may damage the rear window.
■
When the washer fluid tank is empty
Do not operate the switch continually as the washer fluid pump may over-
heat.
306
PRIUS PHV_OM_OM47818U_(U)