I'm sure there's a really good reason for not doing this, but what is it? It looks like there's room to just stick a short-stack foam filter onto the MAF with an adapter/flange and just clamp the assembly onto the TB?
I realize something this drastic could kill the low-end, but those runners are hella-long--it's hard to believe that you'd be hurting for torque.
What's more, you could trim the material under the scoop a little (this is for a 1st gen Outback) to increase airflow towards the filter.
Anyway, please educate me.

 

Its been done before, but mostly with MAP cars. I dont think the MAF will fit with a cone filter, ive measured it cause I thought of the same thing years ago after seeing the MAP DIY throttle body intakes. However you can get a small bent pipe and have it angled to fit, but really you wont get any benifit from it...

 

The problem with making any changes to the MAF based intake, no matter how slight, is that it disrupts the flow of air over the sensor, which is actually very small. By doing, so, you have to have some way to correct the signal back to what the factory ECU is expecting to see for a given amount of air flow. While I don't doubt some flow gains can be made by doing this with your car, without engine management, it will run poorly or not at all.

 

Then is there a way to convert the car to a MAP setup? I assume this would at least entail rewiring a MAP in and using a later-model PCM.