Changes

Take bus number 11 from Vaduz to Feldkirch (rarely controlled, leaves twice an hour: as of 2015 14 and 32 minutes past the full hour). In Feldkirch get off at Rappenweg (Tisis) and walk back to the Agip service area (everyone who goes to Austria will take petrol here and not on the Liechtenstein side - it's cheaper here). Alternatively get off at the border (custom control) - cars have to get slow there, so perfect to catch a ride to Bregenz and Germany.