I started to do a Ecto-1 custom from a Kenner’s Ecto-1 and a Extreme Ghostbusters spare parts.
Started with the Base of the car I sprayed it black interior and chromed out certain points.
cool! im impatient to follow your project, i really loved to do my Kenner Ecto 1 and 1A rebuild!
I am impatient as well as I do it. Yours actually inspired me to do it. I just hope I can do a good job.
So I have been awfully busy with things here but I have not forgotten to keep this up.I have bought some plastic to replace the windows for the Ecto-1 and I have cut out the solid square on the back door.I have also Pre-sprayed the body a black as a beginning so when I paint it white it will hold well.Pictures will be up soon. 
Ok as Promised since I have a lil time Pictures of the Ecto-1 going through the transformations to what I want it to be.This is the Ecto with the primer paint on and the back window panel installed.
Just a word of advice. In the future if your going to paint something a light color, in this case white, its best to use a light color primer like grey. It takes less coats to cover over the lighter primer than it does the darker color 
Thanks for the advice..will make sure of it next time though the primer did not give me an issue i will post pics up soon.
Those are great works (Yours and Spengler ones)!
Still have to do form a Kenner Ecto 1 the Ecto 1 A but I’m not shure to make it like the movie or the original kenner ecto 1-a, since I’ve got ghostbusters 2 mattel action figures and I would be cool to fit them in the car!
What do you suggest?
Thank you 