I had once used the California blade(from BavAuto) to dry a new car and noticed scratches after that. Nothing else had touched the new car. I use towels or a leaf blower since then. Leaf blower is good as blows water from all joints etc where you can't reach.
Do you use car wash soap every time or occasionally? I only use soap(Meguiars Gold) when car is very dirty. Otherwise I rinse with water and mitt. Soap takes away shine no matter what soap it is. The less the better. And no public car washes for my car. If I can't do it...I take to known detailer.