Depends on the car (and the regulatory regime, I'd imagine). My fancy pants 2025 car is happy to leave driver alertness detection disabled, which is handy because it's not good. Of course my ultra base model 1981 van doesn't have any features... it's a lot more fun to drive, other than the engine noise is pretty oppressive on a drive any significant length oh and the floor is missing where the accelerator pedal should mount :P

There'll be firmware hacks to force that mode soon enough.

You wouldn’t download a bookmarklet on your car

"Download NoBeepPro for Android Auto now! It silences all unwanted warning sound, and totally doesn't surreptitiously enroll your car into a residential proxy service or mine crypto currency using your main power or hybrid battery!"

That hasn't broadly happened yet, and it's even less likely to happen in the future with encrypted comms and locked-down firmware increasingly becoming the rule instead of the exception.

That works. I already got so used to disabling ESC on start that I do it unconsciously at this point, can't even recall afterwards that I did it. (My car is old and has a glitchy ESC)

I saw a mod where there was an arduino/lcd setup on the dash of an Audi to turn off the ESC and other annoyances on startup.

I turn mine off quite often. On dirt roads and snow.

Yeah, there are ways if you figure out the manufacturer specifics. Thought it'd be fun to try capturing and replaying CAN messages, gave up cause whatever cheapo CAN to USB adapter I got wasn't working with my Linux laptop. Probably could've figured it out but decided it wasn't worth risking my 2005 Quattroporte with something that was feeling increasingly jank. Autel scanner already gave me all the read-only access I needed, including clutch wear.

I recommend "the car hackers handbook".

Gives you all the info you need including software.

Great start to knowing what the CAN is doing.

That one is good. I did actually start there, just bought the wrong stuff :S

>...until the engine is turned off again

Modern electric Volkswagens (and some other brands) have this amazingly awful feature where lifting your ass off the driver's seat turns off the "ignition". The car just shuts off immediately, AC turns off, CarPlay disconnects, those driver settings reset. Even if I sit back one second later.

...even while driving?

Fairly sure that it won't turn off while the wheels are spinning at any speed -- with the engine off, you also lose power steering in most cases and can trivially cause an accident. Car manufacturers are not this dumb.