Taken directly from here: Subaru FAQs | Find Answers to Frequently Asked Questions
AWD Subaru vehicles with automatic transmission can only be towed with all four wheels OFF of the ground.
AWD Subaru vehicles with manual transmission can be towed with all four wheels on the ground and the transmission in neutral. When towing a manual transmission Subaru behind your motor home, you would put the transmission in neutral and have the key turned to the first position from "OFF". As all new models are equipped with digital odometers, mileage should not accumulate when being towed.