Some Foresters don’t have this feature like our 98S. It just had a single speed intermittent vs the four speed variable one. Thankfully it is a easy upgrade. All the controls are in the wiper arm assembly itself. I simply purchased one that had this feature from Ben @ Hodges, one of our forum supporting vendors. You may be able to do this install without removing the steering wheel but is easier with it out of the way.

Before
http://www.diditmyway.net/SuperRuPics/08/VariableWipers/VariableWiper1.jpg
After
http://www.diditmyway.net/SuperRuPics/08/VariableWipers/VariableWiper4.jpg

http://www.diditmyway.net/SuperRuPics/08/VariableWipers/VariableWiper2.jpg

Disconnect the battery
Remove the two T27 torx bolts that hold the airbag in place. They are on the back side of the steering wheel.
Disconnect the two connectors (air bag, cruise) and place the airbag in a safe place face up.
Loosen the 17 mm steering wheel bolt several turns but leave it in place. Rock the steering wheel and it should pop off. I’ve never had an issue pulling them off by hand but here is more info.
http://www.subaruforester.org/vbulletin/f77/steering-wheel-removal-help-42713/

I like to tape the roll connector in place so it doesn’t accidentally get spun.
Remove the screws from the bottom of the steering wheel column trim assembly and just push it out of the way.

http://www.diditmyway.net/SuperRuPics/08/VariableWipers/VariableWiper3.jpg

Remove two small screws attaching the wiper arm to the steering column.
The next part takes a little finesse. Start by loosening the electrical connector while sliding the wiper arm out of its sleeve. There is not a lot of slack in the wires to the connector.

Assembly is just the opposite. Enjoy your new variable intermittent wipers

Images attached

My how to do here:

http://www.subiegal.com/howto/intermittentwiper/index.php