Assuming that you are asking about the windshield washer tank, it is under the hood, right behind the battery.
We answer this question here frequently. Same place as the front window washer tank, under the hood behind the battery. It is the same tank.
If it's the same as other Foresters there is only one tank under the hood which feeds both front and back washers.
Doesn't the rear window washer use the same reservoir as the windcreen washers? It does on my 1998 Forester. If I keep the reservoir topped up regularly I am never in want of liquid for washing the rear window. ***I had a 2001 (and now have a 2003) Forester. The front and rear share the same fill tank. The 'pickup' for the rear is set higher so tf the fluid level gets low the rear stops working first.
A Subaru Forester's tank can hold about 60 litres or 16 gallons.
Normally the rear fuel washer tanks are located in the trunk area. Should be a panel on the left or right of the trunk covered in carpet that you can pull off. One should have the washer tank behind it...the other might have a jack and tools. Good luck. Although he is correct that there is a washer tank in the back of many cars, Subaru did not go that route. They used the very same washer fluid tank with a second pump and a reaallly long hose between the roof and headliner inside of the passenger compartment. Much easier to fill just the one tank, don't you think? :-) --Ken
The gas tank on the 2012 Subaru Forester holds 16.9 gal..
The gas tank on the 2008 Subaru Forester holds 15.9 gal..
The gas tank on the 2003 Subaru Forester holds 15.9 gal..
The gas tank on the 2006 Subaru Forester holds 15.9 gal..
The gas tank on the 2013 Subaru Forester holds 16.9 gal..
The gas tank on the 2007 Subaru Forester holds 15.9 gal..
The gas tank on the 2014 Subaru Forester holds 15.9 gal..