Hi Martin,
Can you post some of the sample surfaces that you want to see this on? You can just break out one area with the curves highlighted that you would like to see smoothed out.. Since you are already doing patch modeling, I may be able to show you a method to get the curvature you want.. (Be sure to include one of the complex juncture areas Michael is speaking about... The front fendfer area would be easy and not present any problems, but I dont want to lead you with this, if it cant do the other areas you need done)