Googled "Solo 3-wheeler" and found this EV Trike available thru Tractor Supply - https://www.tractorsupply.com/…-spider-72-v-trike-yellow. 90-mile range, but max speed is only 50 mph. Looking at the pics and video, it makes a Slingshot look really BIG! 3 ft shorter than a Slingshot and roughly 12" narrower. Despite the limited range and speed, it looks interesting, especially at the price. A unique vehicle if you live in a golf-cart community (assuming it doesn't break down too easily)!
I was surprised to find a variety of 72V batteries ranging from 20 - 50 Ah on Amazon at prices from around $230 - over $1000.