For some reason the cars in my city appear to be invisible and broken up in parts.
Here's a screen-shot. The only thing I've changed recently is my screen resolution. I've tried changing it back to what I had it at and that didn't fix the problem.
(https://www.sc4devotion.com/forums/proxy.php?request=http%3A%2F%2Fi30.tinypic.com%2Fmagz7m.png&hash=19231db9e7c1cf7b3e8b3c079bb068a15576f0a1)
Try disabling the anti-aliasing settings for your video card. SimCity 4 is an old game and doesn't know how to use the advanced features of current video cards.
-Jan