I’m pretty sure there are ways to mirror an Android phone on to the car’s screen with a rooted Android device.
I will probably only use my setup for occasionally watching something if a long charging session is needed.
For iPhone, I gather an iPhone 5 is best for this as any newer and DRM prevents Netflix from working (possibly also other video apps).
The trouble with this is that the iPhone 5 is fine for streaming video (via hotspot from my iPhone 12), but isn’t really powerful enough to make using the other apps pleasant.
Then there’s the issue that it’s a semi-tethered jailbreak meaning that whenever the phone battery dies and it then reboots, the jailbreak is lost and needs to be redone. So I think it’s only really be practical for specific long trips.
Probably not really worth the hassle but was something to do on a rainy evening in lockdown!