"Possibly" need spigot rings but until you measure or fit can't say (if the OZ wheels are Subaru specific they may be a direct fit.
Just in case
http://www.autoinparts.com/Wheel_nuts,_bolts,_locks,_spacers_and_accessories-Spigot_rings_for_O.E_and_Aftermarket_Alloy_Wheels/c628_897/index.html