In the UK Hyundai give 2 year warranty on wiper blades, may be worth checking with your Greek dealer.
Whoa! It has never crossed my mind that there might be any warranty for wiper blades... 2 years sounds pretty long warranty for something that I'm used to change every six months.
I usually change the blades (at latest) when they start leaving wet stripes to the windscreen. The change takes place typically in october for winter and april-may for summer. New blades in october ensure best visibility in wet and dark autumn weathers. I need to change the blades also after winter as they are no longer good to my standards - frequent deep freezes and salty stuff will wear out the blades pretty well...
I have used several brands (Bosch, Valeo, Champion and various cheapos) and come into conclusion that the expensive ones loose their best edge in 6 months as well as do the cheaper ones. Never kept wiper blades longer than a year, so I cannot comment on their durability for longer time... I usually pick some mid-priced blades, they'll be ok for half a year.
