I think if you want it to be easy to get in and out of, crank forward, or feet forward bicycles are a pretty good idea, like the rans bicycles, the day 6 bicycles, stuff like that. The tradeoff being that the front profile is kind of bunk on those in terms of the aerodynamics, at least, at the cost of the weight it would take to cover it, like a true velomobile. We also gotta ask why you're covering it. If it's just safety from weather elements, that's fine, but it brings other problems, like the enclosed space getting pretty hot if you leave it sitting around, like the shell needing to be visible while still in the rain, and easily see-through, too, which is more of a problem when you don't have windshield wipers, and when your window's more slanted, like what it is on most velomobiles that have windows. If you're adding A/C or heat for thermal regulation, those take up space and weight. Also would probably be a good idea for defogging the window, which is probably a larger concern in an enclosed space where you're sweating a lot more. I dunno, I've just seen a lot of these "bike car" concepts, like the twike, or the podbike, and I haven't seen much come of any of them, because they're just too fuckin heavy, and at least in america, everyone's concerned with what might happen if a driver gets distracted by this weird little bean floating around everywhere, and what happens if they get into a crash. Maybe one might have more luck by cutting weight, adding photovoltaic cells to power some of the electric systems, and then just chasing the maximum aero, like what aptera's done, but yeah, I haven't seen anyone actually tackle the problem in a way that makes much sense. I'm also gonna shout out the problem of these being much harder to park than a normal bike on a bike rack. You already see that with recumbents, but you see that even more with velomobiles, and that inefficient stacking might work out to be more concerning at scale, with mass deployment.

It's also kind of inherently a niche product, with a low market demand, and so that drives up the costs for people who would otherwise be fine with the idea, and that's all maybe a bigger problem than anything I've said thus far. Those who would be interested are probably going to be fine swapping out all the subsystems, and if they're doing that, they're probably just interested in buying your canopy, more than anything else, in buying your shell. I think you're seeing technology play catch-up in terms of e-bikes, but most people at this point are better suited to your standard moped. The honda super cub is still the best selling motor vehicle of all time, and if I remember right, it's not really even close. People are more willing to dress for the weather, and tolerate that, if they're not also powering the vehicle, and working up a sweat.