original chair

Hey all, I recently purchased a used 2005 IS 300. I was doing my first wax job today (using Maguire's quick wax), and noticed that on the bottom side skirts (under the side doors), the feel and look of it was bumpy. I didn't notice this prior to waxing, and was wondering if it is normally supposed to be like this, or did i cause it? Thanks for your time and insight.