first of all: Thank You !
Second: I am following your posts... You are a genius...!...compliments !
Look, I think I choosed maybe a bad sample. Imagine a car from the top...arround the car there is fog ( many sprites that I will locate according the level design). If I drive, and the car collides with the fog, it moves according the direction from where I hit it... like ehm..fog

... I don't know if U have a solution without physics...and not toooo memory/cpu consuming... thanks a lot 4 ur help. Maybe I will put in front a triangular collider...si that the fog slipps a bit to the side..and not bounces just perpendicular like a ball... but u will know it 4 sure better