The ability to generate a curve network with some common intersection points between curves and then have a surface generated over this network, is currently missing from blender. If someone started to develop this, I would be glad to beta test by modelling some vehicle with it.
A good example of that function is what the Jpatch (open source) software already provides. A Blender Python script to generate surface out of a point cloud has recently been published on Blenderartists, maybe it could help too.