Y'know, there is a very simple way to find a towable vehicle. I am somewhat amazed that nobody has mentioned it yet, so I will:
READ the OWNERS MANUAL that comes with the vehicle; FOLLOW the instructions contained therein!
If the Owners Manual says the vehicle is towable, and gives instructions on how to go about it (as, IIRC, Subaru DOES), and the dealer says he will not honor the warranty, show him the book and state that you plan to contact the Subaru Zone Representative about the issue. It really does not matter what they or their technicians think, all that matters is what Subaru states in the Book!
