Not an answer to your software question, but you will very likely struggle with overheating since your phone will almost necessarily be in direct sunlight for hours at a time. If you really need to do this, avoid mounting your phone with a case and try to use a mount that does not cover too much of your phone’s rear surface- cases and mounts can make it harder for your phone to dissipate heat.

I used autoboy for a hot minute when i wanted to run something on my phone to let it act like a psuedo dashcam before I got my android touchscreen unit and hooked up a rear cam and dash cam to it. Not sure if there’s anything better or more recent since I’ve been on Apple since my Pixel 3 XL.

Def make sure you keep cooling in mind. I was kucky that my vents were towards the top of the dash so having a vent-mounted magnetic mount worked in my favor, keep the AC on during the summer, shut the vent off during Winter.

Magic earth

There’s alibi, can’t speak for it tho, never used it.

https://f-droid.org/packages/app.myzel394.alibi/