Screen always on

[tourdetor]

When power and bt connected and in car. How?

[Martin]

You could periodically check the two conditions and execute action Turn Screen On or you could use action Set Screen Timeout: Never when power is connected and bt is also connected.

[Bushmills]

Power connect and disconnect are also available as triggers, firing when one of those events occur. Periodic testing may therefore be unnecessary.
For detecting car use, an NFC tag may be a solution, lest the mobile device supports those.