Light interior and water marks - how to clean?

[gromit]

Hi,

I have a light interior, I think you'd say its a very light grey - however its marked following our wet weather with water marks and I cant seem to get rid of them?

To top it off, my daughter has had an accident on the one seat - so massive water type stain and my other daughter decided to sit on a chocolate bar and thats in the seats too.

I have tried a small area, rubbing with just water, but it almost stains the seat - so I am wondering how do I got about cleaning the marks out?

Thanks.