It seems like the outer dimensions of the infotainment system for both 2015-2017, and 2018, are the same, so there's a possibility that a swap could work. However, since Subaru changed manufacturers for the new infotainment, we have no idea if the connectors in the back of the unit will match up with the connectors leading to steering wheel controls, backup camera, and so on. Heck, we don't even know if it will mount in the same way, and given the price of getting a 2018 infotainment unit, I'm not surprised that no one's tried to check compatibility.