The main difference could be in the style of animation. One might have more detailed graphics while the other a simpler approach. Also, the storylines could vary greatly, with one having a more complex plot than the other.
The connection could be that the 'car wala' plays a significant role in the plot of the car cartoon, maybe as a driver, owner, or mechanic. This could drive the narrative and add interest to the cartoon.
I haven't come across 'ww wala cartoon hindi mai' before. Without knowing more about it, it's hard to determine its quality. Maybe you could tell me more about it?