best thing i have tried so far is to use the meguiar's rubbing clay first to remove all the grime then to polish it off with their polish/wax. main thing was using the rubbing clay as it made the surface very easy to apply wax.
i have tried their cleaning wax and its quite good, but like i said, only after using the clay first (if you have done so, then you dont need to apply the clay to prep/clean the body.
just my two cents.
price in ACE Hardware for the clay is 60rm inclusive of easy apply polish (if you run out of polish just substitute with mild soap). (can last a long time!!!)