We should push for a blanket ban on non-consensual data collection regardless of manufacturer, as well as for changing the terms of service after the sale (such as the introduction of mandatory data collection after you already purchased the vehicle - or any other product for that matter). How / where do we send this feedback to?

Acceptance of data collection should have very high standards. Like written signature after recording of going over all of the terms read out loud. This is only way to be sufficiently sure that consent is freely given.