Clearcoat marring on year old paint

I had my 1997 Volvo 850 T-5 repainted professionally last March as the car had gotten a poor respray on a door, fender and hood which resulted in failed clearcoat. In addition to that there were 18 years of dents and scratches on the car. I recently went to clay the roof and hood of the car as it felt slightly rough to the touch. The clay I was using (Meguiars Mild clay) marred up the paint pretty badly and I had to follow it up with a DA to remove the marring. I never had that issue with any other paints I had worked on so the concept of paint marring from clays was relatively new to me. From my experience with doing paint correction on the car it is on the soft side, but what clay can I use on it (what would you guys recommend) to safely remove the embedded contaminants without marring my clearcoat? Thanks!

Since I'm new here and to give you guys an idea of what I'm working with, here's a few shots of the car.

 

Sounds to me like they re- sprayed with a very soft paint.
Using a mild clay should not mar anything to much. Perhaps use more QDS or lube for the clay?