For XC90 REAR wiper refill, Volvo does not sell refill, you have to buy the whole wiper assembly for about $16. Not a bad price but there is an inexpensive alternative.

I was in a hurry and stopped by local Advance Auto Parts, saw Trico refill. Turned out it was perfect fit.
Trico 47-600 Refills, the 6-mm type, are sold as a pair of refills for $7, so $3.50/each refill.
They are 22" long and you have to cut it to fit.


1. The width of the refill is 6-mm:




2. The key things are:
- Re-use the factory metal tabs so you don't have to cut the new metal tabs.
- Get cardboard and utility knife and cut the new refill about 2-3 mm longer than stock. This is because the stock length is about 15.5" and is somewhat loose: it can move back and forth quite a bit.
- Transfer the old metal tabs over and slide the new refill in, paying attention to the grooves.
- Metal tabs stay above the plastic prongs, which go to the 2nd groove of the refill.

Very very simple, make sure you observe the stock setup, then it is very obvious!