I have always had a problem with scratches when I use a wool pad.
They usually can't be seen until I have the car in my garage under the
fluorescent lights. I've tried everything, cleaning it often, different
compounds, I always got a few scratches that I'd have to compound out.
I liked the wool pad because it's so much faster.
I have finally got a system where I don't use it at all.
I wetsand with 2000, usually by hand and block, then I use a DA, a
4ooo grit pad with water. It's a soft pad by Mirka. I think 3M has the
same thing. After using that the finish is so smooth that a foam buffing
pad with a medium polishing compound brings the shine out so
fast that it's actually faster than the wool pad. And I don't get any scratches.
That 4000 grit gives it a semi-gloss finish that barely needs buffing.