I live in a complex that does not allow car washing at the complex.
So, I use that cheap @ss brush at the do it yourself carwash since they don't allow hand washing at most of these do it yourself carwash places. I usually wash the brush before I even get my car wet to get any junk off of it like rock and what not.
I've washed my car at least 20+ times in the last year and I have yet to get any swirl marks. Only flaw on my paint is that ******in key job done by that @sshole a few weeks ago.
Not sure if it has to do with that I have the Silver paint or not.
On my black Zx2, I had swirl marks after about 2 months and a few car washs at the same place I take my Zx3 for a carwash..
That was one of the reasons I did not want black or any of the dark colors because they seem to show scratchs and swirls marks very easy and those scratch and swirl remover products don't work with a crap.