Thank you for your answers, I'll try that today :)

Wow, thank you! That solves my wiring problem :D I'll try connecting everything today :)

"It should be mounted on top of y1 pieces." Sorry, but that's not really helpful... Obviously it goes on top, but in which orientation, how is it screwed to the wooden part, how do I connect the battery wires to the board... The animation videos don't show nyboard, and there is nothing much in the other videos or in the instructions :/ "Do you mean the ultrasonic sensor as eyes?" Yes, sorry, I meant that. The cables seem not to fit in the head because of the vertical headpiece in the middle, and I'm not sure where to connect it on nyboard. Thank you for your answers!