If you've been looking for replacement wiper blades (not just the insert, but the whole blade) take a look at rockauto.com - they have a great clearance sale on Trico blades (as supplied to and labelled for a 4-letter National Auto Parts chAin) - they have both front and rear wipers for Gen I, II, and III Prius, also V and C. They have regular and winter blades, so if you've been looking for an excuse to replace your wipers now is the perfect time. I got the rear ones in the mail today, it just clips on in place of the old blade. I'm not affiliated with RockAuto in any way other than a very satisfied customer.
