Hello !
Can you tell me how to export product that you manufacture ?
I can manufacture seat and exhaust but stockpile are full, and i can’t export.
Thanks ! 
You cant export them - but if you place a supply conveyor over the output area and connect that to your fit seats station for example the seats will be taken from that collection rather than imported via a socket
also if you stick supply stockpiles nearby and route to them, they can be used as temporary storage for when you have a glut of seats etc 