>| characteristic. KEP says that VW heater controls will not allow the engine's
>| cooling system to work properly and that the front and rear heater cores must
>| either be bypassed or blocked open. I don't care for either option and will be
>| making another trip to the junkyard to see how Subaru manages their climate
>| control.  There must be a reasonable solution to keeping warm or cool as
>| needed  that isn't any more complicated than the waterboxer's plumbing system

        I would guess that the Subaru system works much like the golf system
in that coolant always flows through the heater cores. The amount of heat
that is delivered is adjusted by passing part of the air stream through
the heater and the rest bypasses the heater core. The Subaru might use the
heater loop to circulate coolant when the thermostat is shut - change that
to the only way the engine can circulate coolant when the thermostat is
shut.
        If you could keep the rear valve open, you might be ok. If you
replace the front on/off valve with a selectable T kind of valve (as you
move the control arm, it moves flow from one branch of the T to the other),
you would have an optimual setup...

dave