It's a shame that the CHAdeMO vehicle-to-home inverters don't work on i-MiEV, as confirmed by JoeS, and I'd consider the JDM 100VAC unit more of a toy, as we can more easily and cheaply serve a 1500W load with a 12V inverter. If these cars had cruise control, I'd be tempted to set up some dynomometer-style rollers with gearing attached to a generator head, just as if it were a PTO. Strap the car to the dyno, set the cruise control for the correct generator head RPM (1800 or 3600) and the power output would automatically modulate to maintain synchronous speed with zero risk to the vehicle electronics! (at a cost of some efficiency and tire wear)..
I'll attest to the robustness of the DC/DC converters. I used my iMiEV as a mobile jumpstarter for dead 12V diesel trucks with dual batteries many times without any implications.