I doubt there'd be a demand. We are the vocal minority here on HN. I think it's more likely people like us will buy older cars with non 4G/cell based head units.
We won't be able to buy such cars also in next 10-20 years as by then every manufacturer would have included partial or complete data gathering on their units. If they are doing it so should I so I can stay in business is the concept being followed. This can only be controlled through strict laws, and that is a sorry state of affairs anyway. :(
Low volume manufacturers are exempt from a lot of regulations from what I know. So there'll probably always be a space for someone to make a low-tech car, just not to sell it by the hundreds of thousands.
I see 30 year old cars on the road - daily drivers - reasonably often. They are probably maintained by the owner who now knows it inside and out.
The average millionaire drives a 15 year old car that they bought new (According to "The millionaire next door"). If you actually maintain your car you will discover that they last a lot longer than most people give them credit for. Some years you put more than the car is worth into it, but other years just an oil change.