Another one involving travellers in the desert

[uy707]

Thanks for visiting the previous one, now
same location : somewhere in Sahelian Africa
Same veteran pick-up driver, now standing beside his parked vehicle on a village place. Appearing from nowhere is another westerner.
The latter is fairly young, is all clad in black and travels around with a car side door .
"So" says the pick-up driver "what's happening today ?" and then adressing the strange traveller " Hey guy, can you tell me what's up with you and this door ?".
"Sure" says the traveller " When it's too hot out there, I simply lower the window pane ! "
Alain