Good day, I hope this is the right place to ask this question.
To provide context: A few days ago I found an old Sony Ericsson W205a Phone, it can be used to speak and receive text-messages, but it's unable to reproduce any sounds unless external speakrs (through headphones/usb/bluetooth) are used. I tried with my car radio (that has bluetooth), and it works perfectly fine with it.
However, I keep on forgetting to turn the cellphone ON every-time I get on the car, making it's presence there kind of useless. Leaving it always ON would be a good solution, but the idea of wasting electricity in something I am not using makes me feel bad.
The question: I am kind illiterate in what regards electrical engineering (I'm actually a programmer), but is there any way to modify my SEW205a to turn ON when receiving electrical current (coming from the car), and OFF after 10/15 minutes of complete inactivity? Do you think there is an easy way around this, or is the task is so hard that's beyond my skills?