Finally installed the under-dash heater and AC this summer. Finished it during a crazy hot week here in Fresno, CA where the temps reached 108!! It worked better than the AC in my suv. Very cold didn't even phase the power of the Subi motor when it would click on.
We used an under-dash unit from Renegade Hybrids. New AC compressor, condensor and dryer were added, along with AC and heating hoses. A little flip of a lever under the front trunk and hot water is allowed (or stopped) from the heater core. System works better than the original by far.

Click here for Youtube video:

Video