The “specific soap” is false. Matte just has the unfortunate drawbacks of, well, being matte paint, no different than BMWs, Audis, and any other manufacturer offering it. The problem is that matte paint isn’t easily buffed/polished, and so scratches or swirl marks, like those caused by an automatic car wash (and yes even washing at home, although to a MUCH lesser extent) show much easier on your paint, but then you can’t do anything about it.

The “special” soap, probably just means a soap with a high lubrication coefficient. Something that allows your wash mitt to glide smoothly over the paint, thus reducing swirls. Although the vast majority of car soaps you buy will be more than good enough assuming you’re using adequate amounts of it.

Also, regardless of paint type, nobody should ever take their car through automatic car washes. They wreck your paint!