The US, for example, allows one to build a kit car totally by ones-self, and the waitlist for VIN certification is fairly short. If you want to shortcut the VIN certification you can build a car on a car that has at least 30% of the original frame in tact and piggy-back onto that VIN number with proper certification. If that frame is older than the mid 70s, go hog-wild; you can operate it with a coal engine if you want to.
If you're a 'dedicated individual' that is concerned with having a modern car that is engineered well for safety's sake, then go buy a kit from the hundreds of companies that do nothing but engineering work.
If you're afraid that there will be electrification mandates, no worries -- there are hundreds of startups focused on the conversion of existing ICEs into EVs.
What I'm trying to say : a world locked down to prevent all forms of vehicular autonomy is a lot different than the one we exist in today; it's not something easily predictable to assume when that will end, given the many different venues one can explore to express vehicular autonomy and individualistic choice.