[b3lha]

The regulations concerning import from Canada.

Originally Posted by NHTSA

Importing a Canadian-Certified Vehicle as a Conforming Vehicle under Box 2B
To be imported free of restriction, a motor vehicle less than 25 years old must be originally manufactured to comply with all applicable Federal motor vehicle safety standards (FMVSS) and bear a label certifying such compliance that is permanently affixed by the vehicle's original manufacturer. A motor vehicle that bears a label certifying compliance with all applicable Canadian motor vehicle safety standards (CMVSS), but not with the FMVSS, can still be imported as a conforming motor vehicle under Box 2B on the HS-7 Declaration form to be presented to U.S. Customs and Border Protection (Customs) at the time of entry if the following requirements are met:

* The vehicle is being imported for personal use and not for resale;
* The vehicle is not a salvage vehicle, a repaired salvage vehicle, or a reconstructed vehicle;
* The importer obtains a letter from the vehicle's original manufacturer, on the manufacturer's letterhead (and not that of a franchised dealer), identifying the vehicle by vehicle identification number (VIN) and stating that the vehicle conforms to all applicable FMVSS except for the labeling requirements of Standards Nos. 101 Controls and Displays and 110 Tire Selection and Rims or 120 Tire Selection and Rims for Motor Vehicles other than Passenger Cars, and/or the specifications of Standard No. 108 Lamps, Reflective Devices, and Associated Equipment, relating to daytime running lamps.

Note: To be imported under Box 2B a motor vehicle must be certified by its original manufacturer as complying with all applicable CMVSS. Certain vehicles that are at least 15 years old that are not so certified can be imported into Canada without restriction. Such vehicles may not be imported into the United States under Box 2B.

So it seems you have to get a letter from Subaru in Japan, certifying that the JDM version has been tested against US safety standards. That doesn't sound like an easy letter to get.