U-Haul seems to do very well under the same conditions though. Since the charging port is standard maybe the trailer would be too and U-Haul would be in that business as well. You would just need the car to accept power while in motion and that sounds like a software issue. The high speed charging port could be on the trailer and pass power through to the car, though that would require people to reverse the trailer into the charge station a little tiring after a long drive.

Perhaps it's the threat of theft of the expensive battery - though that should be solveable via tracking.

I don't know.