Two simple (not for me) questions:
1) When to consider the wiper blades to be replaced if they are not visibly worn-out/ broken?. What is the approximate frequency to change.2-3 years?
2) If you are replacing the wiper blades, where can one find the wiper length specific for the car? I could find some aftermarket wipers coming as 'universal' whereas OE wiper blades have different length for left and right wipers (Eg: 24" and 21").