This might not be a big deal if Toyota was the only company contemplating this business model (what's $8/mo, after all?) but I doubt they will be. If every product in your life adds a "small" subscription fee (calculated at 50-1000x actual service costs), things are going to get painful very quickly.
I paid a few dollars for a better dialer, because the Samsung dialer is garbage. Another few dollars for a good calendar app, again because the Samsung dialer is garbage. Hell, I'd gladly pay for a decent web browser. And I say that as a happy Ubuntu user who has been coding for over two decades in VIM, I know my way around FOSS software.
$8/mo may not be a lot of money only because it's just your car doing that. Then you will have your TV charging $8/mo so that you can your a remote controller, $8/mo for the remote of your air conditioner...
The price of a service rarely does reflect the actual cost of providing the service, especially with SaaS margins. And $8/mo is not a whole lot of money if you consider your monthly expenses to use your vehicle.