” With a Rasperry Pi...one could...in theory create such a device. Not unlike a Linux Myth TV DVR for home use. But this would be small enough to install in a car.
Haven’t you occasionally listened to the radio and said, “What the heck did he just say?”
This would be very easy to do but I think the manufacturers would be scared to death to make it for legal reasons (copyrights, DRM, royalties). If you made something that could back up 30 seconds of audio I’ll bet the music industry would get you for “making available a device that illegally records their valuable property”.
My truck’s factory stereo does it.
There are laws that would prevent it. Not the least of which are those that ASCAP has lobbied for and had passed.
Most people ignore them but businesses could be prosecuted for something as simple as piping FM music broadcasts through their stores. But a device that records 30 seconds of FM radio in a car? Never. At least not by a car manufacturer. A private party could easily create one or buy one and install it. The RIAA would never know of its existence.