They aren't as stupid as we thought!
first off, thank you all for your posts, in particular those with photos/videos, they have been a great help.
I have experience the same wiper problem with my 99 Forester and attempted two of the solutions described above, namely that described by SuperRu with the washer and that described by ScoobyDrew with the Dorman part #49447.
Great ideas, I especially love the simplicity of the washer. Unfortunately, in cases such as mine, where the shoulder on the original bushing is completely worn, even a washer won't help. Keeping the actuator arm on the what is remaining of this shoulder requires almost enough force to pop the bushing off the ball-joint - not an ideal solution. After the second time the bushing joint popped off, I went out and bought the Doorman #49447 replacement bushings.
First I tried Scooby Dreq's method, nice video by the way, great help. I trimmed off the flange from the bottom of the replacement bushing, slid it through the hole in the actuator arm and popped it back onto the ball-joint. Nice, it seemed to work great, the play was gone from the wipers and all was well - for a day or so. Unfortunately, it was still possible for the actuator arm to slide off the bushing (toward the motor) - leaving us back at square one. What to do? Well, i could put a washer between the bushing and the ball-joint mount, a-la SuperRu, but that would leave me at risk of the bushing popping off mid-wipe, so I took another look at the bushings.
The are supposed to be universal replacements, right? So perhaps they have been tried on a few cars. I know Foresters aren't the most common auto on the road but, surely, someone has been in this situation before. Moreover, why the flange? Well, it appears that those Dorman guys are not as green as they are cabbage-looknig.. the bushing should be pressed through the hole in the actuator arm and just clicked onto the ball joint.
Ok, well this sounds obvious, so why has nobody done it? Well, because it's REALLY hard to do! It is a tight fight and it takes a lot of BFI. Take a new bushing and try to fit it into the hole and you'll understand, almost impossible. So take a knife and trim the flange back a tiny little bit and still no-go. Now take a cup of boiling water and drop the bushing in for s minute or two, it will soften, now, it should fit in relatively easily (when I say 'relatively' I mean, it will only drive you slightly insane, and you shouldn't need a sledge hammer).
A couple if tips, if you have the time and are enthusiastic, take out the entire wiper assembly and fit the bushing on a bench. If you spend time wrestling with it with the full linkage installed, you will likely twist the arm and damage one of the other bushings (and then you will realise why there are three replacement bushings in the packet!). Secondly, install it dry and then apply grease afterwards. Really, if you grease it you will have no grip on it and will likely loose it somewhere in the depths of the wiper assembly channel.
Anyhow, all-in it's a half hour job, with parts you can get in almost any auto-parts store for under $10. The hardest task is removing the cap on the service hole over the wiper motor, everything else is simple.
For the quickest fix, the bear minimum you need to do is:
1: Remove the plastic cowl under the wipers (right hand side only, no need to remove wipers)
2: Remove the plastic cap from the wiper assembly channel
3: Trim/Heat the new bushing, make the swap and grease.
4: Put everything back and hope it doesn't rain.
Attached are some photos of the job. I hope this helps.
Thanks to all who posted on the topic,