You are correct. The Roadmaster Crossbar-Style Base Plate Kit - Removable Arms # 917-1 has a bracket built in for a 6 pin socket-which is the most commonly used wiring plug when flat towing. This base plate kit is a confirmed fit on your 2005 Subaru Outback Sedan and will work well with something like the Roadmaster Flexo-Coil wiring # RM-15267. view full answer...