I guess it is possible but it means that the sign off screens aren’t always accurate then, because, as examplified by creating a fake new trim, I went through both the car and engine sign off screens and none shown any issue.
This new car was a budget car reusing an engine designed from an older car, out of production. The engine production should not have stopped, but I am wondering if the end of the older car had any influence over it.
There is already some sort of gantt-spirit diagram showing car production/sales/project flow: push the logic and make a gantt with both models and engines. That would make easy to notice such issue and easier to understand the big picture.
I guess part of the problem is that engines production line are somehow tied to cars production. Then when you want to continue using an engine with completely another car and discontinue the original car, problems could arise.
You want to reuse same parts in many cars. Renault Cleon-Font is an example how what I would like to achieve:
made in in 1962, it was used up to 1993, from Renault Floride to Twingo, from 956cc to 1565cc, installed in numerous models such as Alpine A110, R4, R5, R6, R8, R9, R10, R11, R12, R15, R18, Fuego, R19, R21, Express, Trafic, Clio.
I think project flow might deserve an autonomous full page, distinct from the sales pages, to gantt both engines and models, making it easy to control what is planned, in design, in production, out of production.