Now, I can "kinda" see the rationale behind optional features on a car being either enabled via software or subscription. I believe the permanent enable price should be the same as if you added the hardware to the car as an option.
As to why this might make sense for a carmaker. In my work I've visited car manufacturers before, and from what I could see it's quite expensive and adds time to support the various options when building a car. You see they have the main production line, and units are pulled off the main line to fit the options at various points and then reinserted and this causes problems for efficiency and price per unit I think.
So, there's probably a cost saving to making the base car have all the options fitted and having a completely standardized production line. However, the expense is likely going to mean if they sold the base car at the usual base car price they would either lose money, or at the very least, the profit margin wouldn't be worthwhile.
However, if you know a certain percentage of people will want the options, and you can enable it with software later, it's possible building the hardware into every car as standard would work out overall cheaper. They might also be able to upsell to more people by making a subscription option, perhaps with maybe a free trial for the first say 3 months of ownership. That is, they turn everything on for 6 months for free, then revert you to the package you paid for. Hoping that you liked some of the features and will pay or subscribe to keep them.
What I don't like is when this stuff might become ONLY available as a subscription, the overall move toward subscription models for everything irks me a lot. I'd much prefer we still get to choose a package, and have the ability to upgrade later.
So I think my point is, the argument "the hardware is there anyway" doesn't really work, because they are likely going to install the hardware at a loss, on the assumption (backed up by their own numbers) they will sell enough to make a bigger profit overall.
They also likely bake into the numbers that a very small number of people will hack the car and enable the features anyway. The vast majority will not do this, though.