The one from "Goodfellas" is a good one, G-MANN, I forgot all about that one.

Here's a 2 star from a well known, highly acclaimed film that provides one of its memorable moments: http://www.imcdb.org/vehicle_3273-Cadillac-Coupe-deVille-1979.html (Layla by Eric Clapton plays as the camera pans up to show the two dead bodies inside)

Here's another one most people remember: http://www.imcdb.org/vehicle_21619-Morris-Commercial-LC5-1953.html (PS. thumbnail needs fixing)

About the interesting question: my all-the-time deleted cars, for sure.

I guess this scene is quite famous:

http://www.imcdb.org/vehicle_29839-MCI-102-A3.html

Some of James Bond's cars have relatively low rating compared to their fame: they are often not that much used, but usually we still give them at least 3 stars.
But there is the Mondeo about which everyone was talking when Casino Royale was announced/released:
http://www.imcdb.org/vehicle_25674-Ford-Mondeo-2007.html

In everyone's opinion, of the cars we have listed here in IMCDB, what are the most famous cars to ever get one star or two stars? Cars known to the most people but who get the lowest ratings?

I'll start with the green Volkswagen and white Pontiac Firebird in "Bullitt."