Here is what Subaru Australia said about using E10 in B spec Subrau's. Maybe this applies to later "B spec" I don't know how old this was when it was stated.
Quote> All Model Year Liberty B4, Liberty GT 2.0 and Impreza WRX STI 99MY to 05MY models may experience starting and / or drivability concerns if Ethanol Blended fuel of any level is used and therefore we do not recommend use.<Quote
Cheers George
