Tracking Moving Objects In A Video

Hey,

I'm fairly new to jitter but have been teaching myself how to use it through the tutorials. I was wondering if there was any way of tracking a moving object without tracking the colour. Basically what i would like to do with my patch, which is using a video of traffic, is for it to track the cars so that when a car enters the [nodes], at the top of the screen, it would trigger a sample. But the only way i can see feasible is to track the colours of the cars but since there are many colours of cars it would make this quite difficult to do so. Any help or suggestions would be much appreciated!

Thanks,

Andy