arguably the most important piece of the puzzle is this
Lexus GS450H VCU Controller circus board, ha ha the brain of the entire operation that replaces the OEM Hybrid Vehicle ECU
this was reversed engineered by a group of guys from all over the world, if you have difficulty sleeping, I highly recommend their
Lexus GS450H VCU Support Thread on the Open Inverter org site
this is an open source type of effort, where although one of them sells the semi finished product, they offer all the documentation needed for you to go out and build the PCB on your own, and a lot of guys with Electrowizardry degrees choose to do so (me NOT being one of them) I see a kit and I click BUY, and $361 bucks later it's at my door step