R4Connect is a project I integrated in my Renault R4 (before participation in 4L Trophy 2015). It consists of a dashboard and console inside the car, and a mobile application for iPhone.
Using Arduino, a relay board and a BLE module, I built a base station which is able to control multiple tasks inside the car. Using the mobile application, these tasks can be controlled over bluetooth up to 20 meters. Examples of tasks are: flood lights, claxon, interior LED, ..
Inside the car is also some kind of extension, called the “dashboard” which consists of switches, a water temperature gauge and a battery voltage monitor. Every task can be manually controlled using these switches (instead of using the mobile application).