The downside, other than the obvious maintenance/reliability concerns of an aging vehicle is safety. Modern cars are much safer in crashes than 20+ year old cars. [0]
What sucks though is that basically every modern vehicle egregiously violates our privacy [1]
so probably you should re-evaluate your risk assessment: even if you're only concerned with pieces of metal traversing people's bodies, rather than people being maimed, enslaved, raped, and kept in poverty, ignorance, and disease, you should weight the denial of fundamental human rights as a much larger threat than unintentional automotive injury
Maybe do not drive a car with internal cameras if you are living in an autocratic hellhole? Yes, things can change in liberal democracies as well, but a car is easily sold.
autocratic hellholes arise where autocracy is more stable than democracy, for example when the police have enough dirt on activists to keep them from organizing opposition and can persuade themselves that such a crackdown is justified
you can sell the car, but you may find yourself walking to work, and you can't un-record the videos the car already recorded of you; and, if your neighbors still have surveillance cameras the police have access to, you may not have achieved any actual privacy
privacy, in the civil liberties sense, is a collective good, not an individual good
It is an unrealistic expectation that a sufficient number of people boycott modern cars (with internal cameras) to change the vendors' offerings. Besides that, there will not even be a sufficient number of old cars for everyone (everywhere).
Your general point is quite correct, though, and I am avoiding surveillance more than most people.
>The downside, other than the obvious maintenance/reliability concerns of an aging vehicle is safety.
New cars appear safer because the scores include stuff that is not directly related with crash safety, so if a car does not have a back camera, or some "active safety" stuff they will get a very low score. but that does not mean that the car is made of paper and you will be less safe in a crash.