I think it's just personal preference. I remove the seat and then drape a folded towel over it.
When washing, I don't spray, I just let the chamois drizzle over the paint to get it wet and soak and use the towel to control any run off.
When washing, I don't spray, I just let the chamois drizzle over the paint to get it wet and soak and use the towel to control any run off.