The complaints about washer and wipers are quite common among Renault Sandero owners.
The washer and rear-glass panes do not spray the liquid well enough, so a good result may be required by the installation of porceles of the washer (can come from Peugeot, Volvo and some Korean automobiles).
Renault Sandero's staff members are worn fairly quickly without cleaning up a large section of the top of the glass. Therefore, it is better to replace them with larger windshield wipers.
