There are very cool and cheap aftermarket car logo projectors which are installed on cars door. They give awesome image, but their activation mechanism can be a nightmare because they rely on a tiny magnet taped to the door sill, meant to trigger a Hall-effect sensor on the device.

The problem is that magnet constantly gets kicked and ripped off by foot when getting in and out of the car. This project solves that issue permanently by replacing the flaky Hall-effect sensor with a reliable mechanical pushbutton switch.

take a look https://github.com/OrangeTungsten/Car-Logo-Projector-Hack