Northeastern University academics and the nonprofit Consumer Reports unveiled the findings Tuesday, revealing that 19 of 21 major auto manufacturers studied collect and broadly disseminate customers’ private data.

Twenty-eight of 30 car connected apps shared data with at least one third-party advertising or analytics firm, the report said.

“As such, the companies that collect driver data are often the first node in a vast personal data ecosystem.”

As a result, the release said, the web pages can collect consumer data, typically without the driver knowing.

Many automakers also told Consumer Reports that some of the third-party companies the data is fed to are barred from “independently using or selling” it.