I see, it has been explored for a while around the net, though I didn't see anything that said it shouldn't be done, but with the boost><buck converter (does the highlander use one? is it sitting in the junkyard?) it allows 'em to regen to a much lower speed. But for just going forward I'd think it'd be ok, certainly you can add more batteries later if not.
There has to be a lump like this somewhere:
edit, yup, giant boost converter, 288v to 650 (page 70), probably cheap.
http://autoteacher.net/uploads/Toyot...esentation.pdf
edit2: not cheap, if bought with the whole inverter.
edit 3: 650v/1.732050808= 375v delta voltage
80hp*746=60kw
60k/375=160A delta current/motor
*4=640A, 3.5C of a calb 180ah, should be able to handle it for a good while for all 4 motors. calb 180 is 3C continuous current 540A.
375/3.2=117 cells. Looking at $28,000 in batteries. (you mentioned leaf somewhere I think, like 220a fuse on that pack, so like 50 modules in series w/3 in parallel, 150 66a,7.5v modules total, $18k without quantity discounting) )