Here is one way to carry electric bikes by car: buy a larger car and smaller bikes.
The car in the photo is an old style people carrier, the Toyota Previa, a balloon like container, which was in production until the end of last century, ie before 2001, and therefor not only cheap to buy (no more than two to three times the price of a top brand electric bike) but not subject to the increased VED which is to be applied to large cars produced after that date.
As we now have three Mistrals (six for the price of the car at the time we bought them) with 26 inch wheels and only one Dahon with 20 inch wheels I have fitted a bike carrier to the rear door. It is possible then to put two bikes inside and leave space for cases and two outside on the rack.