This is what my page looks like.

Is there a reason I don't have the Add a Movie/Vehicle buttons on my page anymore?

I don't get the Add a Movie/Add a Vehicle buttons on my browser anymore for some reason.

How do I make a page?

Maybe, try making a page with a few main vehicles to see if they are good enough

So, is it enough to start a page for Batman: The Animated Series?

It's immediately recognizable as an 810/812, so it meets the requirments.

It was also at least a two star vehicle, if not three stars.

Here's a photo of a real Cord convertible.

http://good-wallpapers.com/pictures/10296/Cord20Convertible201936.jpg

If it is a well-drawn Cord, it could be listed. But I do not know these cars well enough to judge that. It seems good enough, though.