Not true. Stealth EV can supply a Tesla drive unit that requires absolutely no wiring other than high voltage, throttle, brake, and pre-charge. Straight from their website: "The Stealth EV Tesla Drive Units handle the pre-charge system and main contactors directly from the controller, no external vehicle control unit required! Throttle pedal and brake pressure transducer link directly to the drive unit with NO CAN input required. Just hook up high voltage, throttle, brake, and pre-charge/contactor box and drive!"
Tesla Small Rear Drive Unit | Motors and Controllers | Stealth EV
Using a programmable power distribution box like a RacePak SmartWire massively simplifies wiring for the coolant system, HVAC, and other 12V accessories. It doesn't get much easier than that.
