Hi Kenmo, cars tend to be a pretty difficult area. NURBS modeling is at its strongest and easiest when working with mechanical shapes that are well defined by 2D profile curves. For organic shapes like a face for example, that's not defined very well by just one 2D profile curve, it's constantly changing. That's when the sort of "sculpt by tweaking a 3D point cage" polygon modeling approach tends to work a lot better. Vehicles can be in sort of a gray zone somewhere in between.

Check out here for some links to previous car modeling discussions: http://moi3d.com/forum/index.php?webtag=MOI&msg=6504.2

Also there are some general NURBS modeling tips here for people coming from a poly modeling background, those may be helpful since they go over some of the big differences in the preferred modeling strategy for NURBS (basically use 2D curves and booleans) which is very different from sub-d modeling strategies:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael