Clay bar, I was a bit sceptical at first.

2xtreme1

yeah, you have to make sure you fold the clay once one side gets heavily soiled. Also, make sure you maintain your car with a good coat of wax on a regular basis. Doing so, at least in my experience, will cut back on the ammount of clay bar that you will need to use the next time you treat your car. The first time I clayed bar my Z it was heavily soiled, so I picked up a lot from the clay bar. The second time around, when I decided it was time for a clay bar, the paint already seemed really smooth. There was only a few spots here and there, which needed some attention.

( I use my car mostly on weekends, so that could be another reason why on the second time around not much cotaminents were picked up)