You should start by reading Subaru's Privacy statement.
https://www.subaru.com/company/privacy.html
If you still have questions, you can attempt to contact Subaru of America and see if their customer service team is willing to escalate your question related to privacy.
If you still want to remove GPS tracking capability, I'd locate the GPS antenna and just disconnect that.
For what it's worth, most cars sold these days have some sort of constant LTE connection that sends telemetry data back to the mothership.