Recently three warning lights (Engine, VDC traction control and park brake) showed up on my MY10 Diesel Outback. The local dealer right away said glow plug failure and showed me the two on the righthand side of the engine that were faulty.
Although the vehicle is 18 months over the 3 year warranty they told me the repair would be done under a "Goodwill" warranty and the cost to me would be for diagnosis and road test.
Four glow plugs and the main 50 amp fuse were replaced and the bill for the diagnosis/road test was under A$200.
My point is if this can be done under 'warranty' here, it should be available for any other Subaru diesel that develops this fault.
Now this fault has been resolved and the earlier recall for a missed hole in the gearbox during manufacture, the vehicle is being replaced before any other issue arises.