This is a little off topic, but, I just bought DW an ebike. She suffers from ankylosing spondylitis and could no longer pedal her tricycle without a lot of pain.
Anyway, we previously carried her tricycle and my mountain bike in the bed of our GMC Canyon. Both bikes were the folding type and fit nicely in the truck bed.
So when I researched ebikes, I concentrated on folding ebikes.
We settled on a nice, but pricy bike called an Addmotor. Folded up, it fits where the tricycle used to.