The Easy Sidecar 3 from Mod Bikes is probably the coolest bike I've ever ridden.
Mod Easy Sidecar e-bike review: Too much fun for one person!
It resembles one of those old World War II motorcycles, with its 'fuel tank' (where the battery is) and nice retro sidecar, complete with a small saddle, seat belt and mounting hardware that is easy to attach and remove.
It took me, a newbie in bike assembly, about 4 hours to assemble the bike and sidecar. The instructions came in both written and video form and were fairly easy to follow.
Once assembled, I took the Easy Sidecar 3 for a quick spin and quickly discovered that riding a bike as cool as this one was going to take some practice. Even with a little weight in the sidecar (I dropped my paddleboard in as if I was going to the lake), the way you ride a sidecar bike is very different than a typical two-wheeler.