Same here, got my 06 Sti in Sept, got service book last week after getting the 1K service done, though Ian Grieves said they would stamp it next time. As for the warranty think I am only down 2 months on the full 3 years as they obviously bought the car in July from Cyprus. 6K is a massive saving, and alarm was £250, tracker £300 and nuts £30 from halfrauds.
So far so good! Dont know if I need to do anything to register with Subaru UK or whether MP has done this - filled in some forms at the place in Glasgow for subaru....