I just took off one of the rear heater hoses, and went to the local (you
oughta like this one) Farm and Fleet.  I rummaged around the plumbling
section till I found the elbows and the hose.
BTW use CPVC 'cause regular PVC will deform with the heat of the water.

I havn't replaced the core yet, I might cobble something togther with a
non-vw core, but in the meantime I am enjoying the extra space under the
rear seat that the heater used to occupy.  

Dean