> turn off remote access services, dig through the infotainment to turn off what I could

This is never enough. You can't trust a software switch. You need to remove the hardware capability if you want to make sure the car isn't spying on you. In the best case, the telematics box has it's own fuse, and that may be enough. In other cases, you need to find the box and unplug it. The service manual will have it's location. In some cars it's easily accessible, in others less so and you need to remove the glove box or part of the dash. Dealers will probably refuse to do it, my advice would be to DIY or find an independent mechanic who will do it.