But theft of cables between the charger and the car will go up. With high copper prices, these will disappear unless you have a way of locking them up.
Though the concept of being able to reach 4 vehicles at once seems nice, it will only entice rage wars when someone unplugs your car to charge theirs. Imagine getting "iced" by 3 other EVs. A better solution is a mechanism where up to 4 cars plug in simultaneously and the charging is split evenly to cars as they are able to accept the current. So if 4 Tesla's pull up, they all draw evenly sharing the maximum current of the source. If one leaves and a volt pulls up, then the volt gets 16A and the Tesla's pull the remaining evenly (20-40A each). When a battery is full, it drops out and the remaining current is split amongst the remaining.