This particular model bares a few distinct differences from the recently revealed STI, incorporating many trademark features of previous models such as foglight covers and a front lip spoiler.
This has led to speculation that it is in fact a prototype version of a new STI variant, tipped to be the sedan version of the STI spec C.
This idea is supported by the fact that the wheels appear to be the same as the current STI spec C hatch.
Either way, it is almost certainly a development prototype of some sort with what appears to be a wire emerging from behind the grill and taped down behind the license plate and onto the front bumper.
To check out the rest of the photos and a video, visit BridgeToGantry.