Automotive groups, forums, clubs that focus on your individual brand of vehicle, or better your specific vehicle.
Brands generally keep the same style or type of system across their range, so if it works for one car in the brand it is much more likely to work on another.
My Chevy volt, for example, has a separate controller from the engine controller, and I could just airgap(unplug) it.
Others you may have to remove the antenna, replacing with a dummy load to not permanently damage the circuits.