Hee hee, I didn't manage to deliver the message I wanted to
I didn't want to say a cat on a car as inside of it but physically on top of it (you know, when you see a cat on a roof or on a hood of a car).
That is fascinating and scary at the same time. I had learnt that using は or が you can actually deliver a difference stress on the message delivered...now also on the position of the word. This will take me a long time to understand it.
Thanx alot for your explanation.