Sounds a good plan, yes the yanks have done a lot with electric cars.
The Tesla motor and diff were not to bad, I was taken by surprise to be honest on the cost of only 6 batteries plus all the control gear, wiring, charger etc etc...
At the time ( Last Year ) I was looking at £18,000 + for 300bhp.. and I would have done all the fitting and wiring as well.. I really loved the idea but could never justify those costs.. ( it was on a race car not my Amazon) as im looking at 350 to 450 BHP for a lot less from a normal turbo engine.
But I'm really looking forward seeing how you get on as the idea did enthral me due to the instant response and torque of the Electric motor, good luck
