I haven't re-read the whole thread but I think this counteracts the topic drift:
How do you make the video go to 16.28? That's where they talk about the Torquetrends 2:1 planetary reduction box. It's splined for a Siemens or UQM motor on one end and has a driveshaft yoke on the other (held on by a grade-8 bolt so you can match the driveshaft).
This is about the simplest (though spendy) motor installation I've seen; for a open driveshaft car, anyway.