@devilskreed also mention it
when shud v use detailing clay??
Take a plastic baggie, stick your hand in it and rub you hand on your clean paint. If it feels rough, you need to clay. Claying removes contamination such as industrial fallout, rail dust, and embedded debris. This contamination sits on top of the paint surface and a clay bar, when properly lubed, shears off the top of the contamination, leaving a clean and level surface.