Solid still requires data to be stored somewhere thought, someone needs to host the pod -- and the chances are, it'd still be one huge vendor-owned pod.
You could say: "but I want to configure my car to upload data to a different pod" -- but this is possible today. If there were an interest, the car could ask for WebDAV / sftp / webhook address + credentials, and put telemetry there. But manufactures don't do that because there is not enough interest for this feature to justify development + support costs.
The problem is UX: if data privacy laws forced the issue, I think we could come up with a nice way to specify the pod that is accessible to non-techies.
You could say: "but I want to configure my car to upload data to a different pod" -- but this is possible today. If there were an interest, the car could ask for WebDAV / sftp / webhook address + credentials, and put telemetry there. But manufactures don't do that because there is not enough interest for this feature to justify development + support costs.