Isn't it just painted dark? We would like the roof box to be a bit different. That means the slats should be arranged crosswise, not lengthwise. Additional cost about €500. But we will see if there are other options.
Since wood has to be painted every few years, UV and heat-resistant plastic profiles are actually used for this. For example Heering, the brand name is Mammut profiles. There are also online manufacturers, e.g. fassadenpanele24.de, that’s where I got mine. White is cheap, foil-coated anthracite is expensive. In the long run definitely cheaper than wood.
That could be, but I would ask specifically. Even if the roof box is made of wood and impregnated, you still have to maintain it regularly. That is not necessary with plastic.