That means he planned to use a differential, driveshafts and all that junk.
Two (or four) smaller motors mounted in the hubs will give the same power, without the loss incurred by the differential.
You also get rid of the weight of all that scrap metal(axles and differential).
The big problem is that you need more advanced motor controllers and battery management.
(Which is why you don't find many multi-motor EL-car in the market.)
The motor controller is made for a golf cart...
Sure, they're robust, but efficiency has never been very important on those.
As long as the batteries last the day, they can be as wasteful as you like.
Marine grade batteries?
Left on trickle charge for all that time?
How many AHs is a 'size 29' battery anyway?
If you want something that CAN be used(albeit still a 'single motor' design), stop by www.goldenmotor.com (motors, controllers and battery packs, including complete kits for assorted conversions) or www.batteryspace.com (loads of cells, chargers and good info)