You forgot to mention one of the most important features of an iconic movie car: car trouble. The entire plot of back to the future 1/3 hinges on the delorean being broken. The bluesmobile falls apart at the end of Blues Brothers. Ecto 1 is a complete piece of junk when it's introduced. The car in Ferris Beuhler gets driven off a cliff. The list goes on and on. I know Bond is the exception, but it's pretty much the exception.

It's like the millennium falcon. If something is glitchy, twitchy, destroyable and/or falling apart - it feels more real.