heres what i believe to be the final page in the book for this story, please correct me if the information or I are wrong.
it appears that the ecto 1 a was repurposed as one of the few cars in AFTERLIFE, and theres good information to back it up. heres a hemmings article stating such, and there are also pictures jason reitman was posting as teasers for the car that shows the ecto1A bumper on a shelf, implying that it is the ecto1A being used and turned into a version of ecto1.
https://www.hemmings.com/blog/2019/12/1 ... d-ecto-1a/ here is the link to reitmans instagram, where if you scroll down, you see a black and white picture of an ecto grille, notice the bottom driver side light that isnt on the car in the afterlife trailer, but appears only on ecto1A.
https://www.instagram.com/jasonreitman/?hl=en