Where is the fill up thing for a 2001 Subrau Outback Station Wagon.For the rear Window?????

When u lift the rear hatch, it is either near the molding along one of the sides where the hatch meets the opening. There will be a little hole with a rubber gasket, that is where u pour ur windshield solvent. Otherwise, when u open ur rear hatch look inside to the right (or left) on the side of the hatch areas interior wall. There may be a little compartment door that u open & there will be a cap that u lift off to fill.
Hope that helps, l once had both a Subaru wagon as well as a ford escort wagon.just can not remember which was which.
Good luck.

There is not one, they use the same washer bottle in the front. Check the manual.

Yep, your service advisor is right. The rear washer and front washer share the same reservoir. The pump for the rear washer is located higher on the tank, so if you run out of washer fluid in the rear, you know your reservoir is getting low.