Range extender motors should have been easy to rent and much cheaper for long trips than a full car rental.

It would be very interesting to me to have a small sedan BEV with a rear charging port and an optional flat trailer with a large battery and room for luggage/furniture. The battery would be plugged into that car while driving. I'd want the trailer rentable from the dealer for occasional long trips. BEVs seem to have powerful motors, there must be something else with the economics why this isn't a thing.

Everyone wants to rent that trailer at the same time. That is Christmas break, spring break, and summer vacations. Most of the year it is going to sit unused and so you're going to have to buy your own trailer if you want one not rented because they're just not the economics of it. You'll be paying for it either way because you're going to be the only user.

RVs are where I would think this would make the most sense. People with a travel trailer already have a heavy trailer and they want a lot of battery to get it anyway. beef up the axle a little you can put a thousand pounds of battery on you get more range when you're towing and if there's any left over your RV can run on battery power. It's also very common for them to plug in once they get where they're going and so they can charge on 220 volt power that's already at the RV park and be charged and charge your car while you're at it overnight.

I noticed that they are selling RV trailers that help haul themselves, and now electric trailers for semis.

https://electrek.co/2026/03/26/lightship-electric-rv-trailer...

https://electrek.co/2025/06/30/pebble-begins-deliveries-elec...

https://electrek.co/2026/05/08/really-quick-charge-with-rang...