Do you know your trim level? Manufacturer often offer different sounds systems and the lower ones are missing some speakers. And since producing a separate panel without the holes would be way more expensive, they're using fake covers for a fraction of the cost.
And there is Logitech level BS where they spend extra money to fake tweeters... (Logitech Z333)
According to the Seller this is the Full package, but even at the time I doubted that as it has some things missing like those neat Auto Seatbelts, heated mirrors and the secruity alarm. At the time I just thought its a thing of it being an older 92' model, but this tweeter situation has me believing otherwise....
Either way, gonna have to build in some proper ones soon
Subarus of that era are a mixed bag when it comes to wiring. If it was a sub harness with the speaker wires (like a separate radio harness) it’s probably not there in a lower trim.
If the speaker wires are in the main dash harness(es) then it could be there but is probably taped back to the bundle somewhere close to the speaker hole.
As an example, My 97 Impreza L had most of the wires for cruise control; the on off switch connector, brake and clutch switch plugs, but not the sub-harness wires for the steering wheel controls.
Autoseatbelts were likely a lower trim option. They had to have those or airbags and airbags were more expensive. So that's an indicator it may be slightly higher trim.
I worked in an import dealer for a while back then, lots of upgrades installed by the mechanics, saw how sub harnesses and components to complete an upgrade came as a package. Those guys were fast, knew the shortcuts to get things installed without taking half the car apart.