Help newbie

Hi im new to the game but hooked my question is this i have a successful sedan line running all the production upgrades etc now i have set up a new line to build suv only can i merge this line into the sedan line at the paint phase??? I have tried but the suv line is showing as next slot not found the fit wing mirrors slot on the suv line the conveyor is correct and merges with the sedan line after the fit wing mirrors slot of the sedan line (dont know if the screenshot has worked!!!) any help would be much appreciated


update got it working had to delete the last slot fit wing mirrors on the suv line and put a new one down for some reason its working now