On Thu, Mar 18, 2021, 10:36 PM grarpamp <grarpamp@gmail.com> wrote:
https://www.vice.com/en/article/k7adn9/car-location-data-telematics-us-military-ulysses-group
https://www.documentcloud.org/documents/20515640-ulysses-document

A surveillance contractor that has previously sold services to the
U.S. military is advertising a product that it says can locate the
real-time locations of specific cars in nearly any country on Earth.
It says it does this by using data collected and sent by the cars and
their components themselves

Some personal experience: although nowadays cars have electronics that can broadcast their location in various ways, additionally the spark plugs in the engine emit a wideband signal each time they spark, like any other spark does.