Don't want to rain on your parade either…. but I'm of the school of thought that says “go white or go home.”
The key to building a successful ecto replica is making it recognizable. Shape and color are the two most important things. Having a teal ecto is like having an orange batmobile. You really need to get in touch with people's nostalgia of the movie, make it familiar.
Too much variation and your car will end up like this thing
getting laughed at wherever you go.
Take the high road, man! Paint it, even if it must be done with krylon!
If you do enough coats and buff it enough, you could also use rustoleum. This technique works, but you'd have to apply one coat a day, and then buff it the next for about a month. On the plus side, it's only $50.