This analogy doesn't really work because car are inherently much much safer than jetpacks just by the virtue of the fact that an error or failure or accident is almost not fatal. 0.7 percent of car accidents are fatal. In serious plane accidents, what laypersons would call crashes, the fatality rate is about 55%. Which is actually not bad considering, but not imagine if a plane was instead not this highly regulated bus-like thing that makes set routes and piloted by only experts, but something anyone can buy and fly like a hypothetical consumer jetpack. How many jetpack accidents are something that don't result in dismemberment or death? It must be a low number.

From a safety perspective, you're going to be in a little bit of trouble because this hypothetical industry will have profiteers and customers that simply won't let you regular them much. Cars are a special case because nearly everyone rides in them so safety concerns (thank you Ralph Nader) are politically easy and the capital owning class have a hard time pushing back on stories of dead families in terrible accidents. The capital owning class finds it easy to push back against regulations on motorcycles, thus maximizing their profit, because even people into motorcycles don't want crumple-zones, roll-cages, big flashing lights, bumpers, etc because it hurts the aesthetic and experience they buy motorcycles for. Lets remember it took 60-70 years of motorcycle popularity before helmet laws got popular. That's a very slow regulatory burn.

So the jetpack is a lot more like a motorcycle. Even on well regulated roads full of safety devices they're still death traps because any vehicle without a "cage" is simply dangerous and impossible to be made safe. The NHTSA: For every mile traveled, motorcyclists have a risk of a fatal accident that is 35 times higher than a car driver.

So no, you probably can't car-ize a jetpack because a jetpack isn't a car. Its own unique mode of transportation and one without a cage and something inherently unstable. I imagine your best case scenario is many times the risk of motorcycles. This is why investors, the living arm of capitalism, refuse to mass-fund these deathtraps, but they'll fund any gimmicky crypto or social media thing. I don't think a successful jetpack company wouldn't want to car-ize it anyway. It would take away the appeal and the profit incentive would demand they continue to make them as sexily dangerous and performative as they can get away with to increase that appeal, thus sales.

You also have the larger regulatory and public safety issues drones have. They can't stay aloft without power and come crashing down without wings or autogyration to helps them down. So in populated areas it would be irresponsible to have these flying over the heads of people.

If you have free time, go ahead and visit /r/weirdwings or /r/weirdwheels. There's no shortage of "innovative" death-traps out there that failed to penetrate the market because they're just too dangerous.

Last but not least, single-person transportation tends to be the kiss of death anyway from both a practicality and cost perspective. People are social, have significant others, children, elderly to take care of, etc so the single-person vehicle has to be something you own ON TOP of owning a car or two. It doesn't replace cars, so a prospective buyer is someone who has to make car payments as well as jetpack payments. What percent of Americans can afford this vs people who can afford cars and the occasional airline ticket? Currently, an affordable jetpack is $200,000. If through the miracle of mass production you get that down to 1/2 or 1/3rd that, its still the cost of an expensive luxury car. What market are you appealing to even if you iron out some of the safety issues? Who is this unicorn who can afford this and would want it, especially considering the wealthy tend to be old men unfit to pilot something like this safely and with comfort, the same way the average Corvette driver isn't hot 20 something guys like in the movies, but older men close to retirement.

Google says the average age of a corvette owner is 61. Do you really want 61 year olds flying over your head in Iron Man cosplay that actually flies? Knowing full well if their arm muscles give out then their vector radically changes and more or less turns them into 70+mph human missiles aiming for the ground?

In a country that has traded efficient public transportation like intra-city light rail, trollies, and fast regional links for car culture, well, you're kinda stuck making car payments then. Not enough people can spend $100,000 on a jetpack the same way we all don't have a Cessna waiting for us as the local regional airport. The money ain't here even if you can fix safety and the absurdly low flight time of just a few minutes. The sci-fi fantasy of flying alone above a city is not only technically difficult, ridiculously dangerous, but economically impossible for all put the wealthiest.