Recommendations when installing the phone inside the vehicle:
1- Install it in an area where the temperature does not exceed 50º C (to avoid problems with the mobile phone battery) the areas of the passenger compartment are not the most recommended, since in summer and in the sun the interior temperature can exceed 50ºC.
2- Android models that have the option of scheduling an automatic power Off/On time of the device are the best option (Android 4.0 to Android 5.0 but depends on the manufacturer). Ideally, the device should be shut down for 5 minutes a day (for example, from 4:55 to 5:00), this way if the device is blocked for any reason (after all, it is a computer running 24 Hours a day), in less than 24 hours the system would reset itself, ensuring that the system continues to function. If the device on which the program is installed is rooted, the application itself does this resetting every 24 hours.
3- It can be installed hidden in any part of the vehicle where the 12 volts of the battery arrives, you only have to connect to the 12 Volts a car charger that delivers 5 V. You can do it yourself with a normal car charger, a soldering iron and two pieces of cable or you can buy a specific one online for very little money (look for at any online store "DC 12V to 5V Micro USB Adapter").
4- Choose a site where the device receives enough signal for both communication and GPS.
5- Even if you are not going to use wifi communication, leave wifi activated because it improves in enclosed spaces and with little GPS signal the precision of the location.
6- Leave automatic updates on Play Store, so that each time there will be a Carwatchman update it will be downloaded automatically. It is convenient that you delete and deactivate any other application that has the phone and you will not use it so that it does not consume data and also it is not updated automatically (be careful not to delete or deactivate Play Store or Google Play Services since they are necessary for the good functionality of the application).