Post your SolidWorks file you are trying to bring into ANSYS for us to have a look. Use the Advanced Editor link in the upper right of the dialog box to post your file.
I have attached the geometry file. Thank you in advance for looking at it. The biggest problem with NURBS surfaces is on the side pods as far as I can tell.
I don't know ANSYS, but based on what I see in your file, I would say the issue might be that you have very few spline points in the curves. If you display the curvature combs, you can see there are very sharp transitional areas.
You used the spline handles exclusively to shape the curves, which are causing higher "stress" areas. There is no way in SolidWorks to change the degree of curvature by entering a value for the curve, although some add-in surfacing apps might allow you to do this.
So check with the ANSYS people first, and ask them if adding points to the spline might solve the issue. If they agree, this will take a little bit of work to preserve the overall shape you already have by adding points and moving them to maintain the shape without using the spline handles as much.
Unfortunely, SolidWorks offers no control over the number of control points (the underlying math of the surfaces) that define NURBS geometry. SolidWorks also creates very "heavy" geometry vs other more decicated surfacing packages such as Rhino and Alias (which both offer control over the number of control points).
The only option to modify the geometry would be to re-model the body in software the offers control over the math of a surface.
The attached image of Rhino screenshots shows the problem. The top screenshot shows the controls points (white dots) of one of the car body's surfaces as generted by SolidWorks. The below screenshot show the same surface rebuilt in Rhino with a much simplier underlying structure for the same shape.