Black marks - white car

[Humpy D]

Was cleaning the OH's white car at the weekend and noticed a lot of small,black marks after the car was washed. These weren't tar as they did come off either with a bit of vigourous work with the sponge or an old toothbrush.

I would like to find a better way to remove them - should I be using a clay bar? If so, is it ok to use one of these and then simply dry the car or do I then have to apply wax/polish as the clay bar would have removed any that was still remaining?

[Humpy D]

Thanks all.

Yes, I know a toothbrush isn't the best thing to use (understatement!!) but it was the only reasonably non abrasive thing I had to hand.

As for using a sponge, but I do use 2 buckets!!