I've owned Pi's since the first generation and have had various test rigs made from what I had to hand including stepping the voltage down from 12v and various bits of lego holding the components in space. Whilst good fun it is not the safest approach for humans, animals and the components.
I have purchased a Pi 4 with official touchscreen which will become an Android Auto car PC (nicknamed
Otto). Otto will eventually live in a custom made enclosure in the vehicle but while he is being configured I would like him to be cosseted on a nice test bench with a 240v AC supply going to the 12v DC to 5v DC 3amps that will be the input for all Otto's power needs.
What recommendations would you make about the 240v to 12v power supply and avoiding static so I don't end up baking my pi? Should I bear anything else in mind (I am neither an electrician nor an electrical engineer) such as a capacators to smooth his power supply and cut out alternator noise?