I have a soft spot in my heart for anyone who wants to provide a pic-heavy tutorial for any E-conversion, but...there are some issues with this, though I still do applaud the effort.
If there was only a very small difference in the efficiency between this and some of the more conventional E-conversions, it would be a viable alternative for anyone who had some DIY skills and a tight budget.
not everything that we have learned on E-bikes and E-motorcycles is directly transferable to E-cars, but enough relates that some basics need to be considered. E-bikes have some fairly happy Direct-Drive (DD) hub users because the weight of a bike is low, the speeds are typically under 30-MPH, and the battery pack that can provide a 30-minute ride @ 20-MPH (avg, : approx 10 miles)..is reasonably affordable.
Add the weight of a car (even a light one). Then, add the speed needed for even a 45-MPH street-only EV (no 65-MPH highway driving), then the killer: add the needed range. Ten miles between charges, if using lead acid, you'd need a 20-mile pack to get 10, and even for a measly 45-MPH, I'd recommend 72V as a MINIMUM.
The only place for a hub-motor on an EV-car is to add the temporary capability for AWD on the normally NON-driven axle. Get a small and light FWD car with a manual trans. Adapt onto the transaxle an appropriate motor. Even just using two of the gears in a standard 5-speed trans would have a huge benfit to battery range, and keeping down the twin evils of motor-heat and controller-heat.
Many gasoline engines run from 3,000-6,000-RPMs, so most appropriately sized E-motors would stay in their efficient range with no changes to the stock differential gears. From 0-30 MPH, hub-wheel motors on a car are converting way too much of the batteries W/H into waste-heat. Short range and poor performance.