That brush leaves marks and scratches. Imagine some dirty 4wd being washed, leaving pebbles and mud inside the bristles, then you drive up and run that same brush on your car... Ive washed my brother's commodore there for ages and the paint now sucks... Also when you swing that brush around it can leave dents in your paint...
I think im gonna get those karcher things and use that... I heard they go for 90 bucks...