I had a 2000 Subaru Outback. The head gasket went at 120,100 miles. Turns out Subaru had a secret warranty good until 120.0K miles.
They offered me some mickey mouse additive to pour in the radiator that was supposed to help seal the gasket. Didn't seal the gasket, but it did a great job of plugging up the radiator. So I got to replace it at about $400., and the dual head gaskets at $1200., plus the cost of renting a car for a couple of days.
The gaskets were bad for the '99-'01 models. I wrote the president of Subaru N. America about this pathetic level of support, and never got a response.
For better or worse I recently bought a 2009 Subaru Outback. I learned then that Subaru had researched the problem about bad gaskets, and discovered only six months earlier that it was due to phosphorous in the coolant that was eating them up.
Rather than getting a new supplier of gaskets, they chose to market their own phosphorous-free antifreeze (at $25./gallon), which is supposed to 'help' but not entirely prevent gaskets from leaking.
Glenn Cahn