in UK they are backordered apparently until 2024 at CPC/Farnell, other suppliers can’t even give a date when they will be available. When I looked on RS (Radio Spares) I did seen a similar SBC known as the Okdo Rock being recommended - I’ve not used it and I expect any software would need some recoding but the hardware does look quite similar in capabilities…
I don’t know if there is already some light sensor in the car but on my 2015 VW Polo (which doesn’t have automatic headlights) if its too dark outside (even in daytime, due to bad weather or early nights) the lights of the dash are dim (you only see the needle of the speedometer and tacho). So there is still the obvious cue to turn them on. Perhaps its more common in European cars?