Hello John, This is an interesting one. The way towing capacity is assessed will be different in the US to EU. There could be some unseen differences in the vehicle that affect the tow capacity. However I believe that UK statutes will look at the published figures for the model of vehicle in question, as the product is of US specification, it will apply the US figure. Daft as this may seem, the courts cannot make assumptions about likeness. If you were to contact Subaru, and ask for a review of the towing capacity, and they agree to up the limit, the change must be fully documented and related to your vehicle (referenced to VIN and Chassis numbers). I think Lutz may wish to add chapter and verse to my answer.