So much for putting my phone in a Faraday bag in my car. Car still detects the phone via Bluetooth. If I turn Bluetooth off, phone turns it back on after a while. So far car cannot detect phone if it is powered off but who knows. That could just be for calls & texts. Phone even off but with the battery still in it could have one or more chips reporting various sensor or location data to the car not for my use but for human herd tracking purposes. Moo on queue!
@User1984 Most people don't completely understand the Faraday cage and results of the experiments with them. For example, a car and an airplane act as a Faraday cage and can safely divert lightning around the craft but you can still get cell phone reception inside of a car. Depending on what you are trying to block makes a huge difference. Also, the signal strength of what you are trying to block makes a difference as well which is why thick metal sheets such as lead plates (very dense) can block a lot more than a thin film aluminum bag can. So while a Faraday bag may work in regards to blocking a lot of the signal to and from a cell phone and even enough in a low signal area that it can't connect but if you are close to a cell tower such as most that are located in cities then don't count on the bag to protect your location data as it may or may not do so.