I wonder if this is like the infamous vanagon leaky head syndrome.
> CAMPAIGN MESSAGE
>  As a precautionary measure, SUBARU OF AMERICA, INC. is recommending 
> that a special conditioner be added to the engine cooling system of 
> certain 1999 through 2002 model year Subaru vehicles equipped with 2.5 
> liter engines. This recommendation, which applies to your Subaru 
> vehicle, is made to prevent a possible external coolant leak at your 
> vehicle�s engine cylinder head gaskets.
> <snip>
> BACKGROUND INFORMATION
>  Your vehicle�s engine cooling system contains liquid 
> coolant/anti-freeze. Over time, it is possible for small external 
> coolant leaks to develop at the engine cylinder head gaskets. This is 
> the result of normal expansion and contraction of engine components 
> caused by the heating and cooling of these parts. To prevent coolant 
> leaks from developing or to correct existing leaks at the head 
> gaskets, a special Subaru Cooling System Conditioner should be added 
> to your vehicle�s cooling system.

boy am i glad that SoA has good warrantee/customer service.
-steve-v
santa cruz