Ha! This is right up my alley. When I model vehicles, I use the Alias/Wavefront software Autostudio. The software runs on Win2k. It is "The" industry standard for modeling automobiles and it isn't all that hard to figure out after using it for a couple of months, but it is the most powerful 3D modeler out there. The retail price is quite high for non-students(10k and up), but until Oct 30, it's very inexpensive for students ($195). Their website has some good tutorials on how to build cars with their software (the one that comes to mind is showing the basic construction of a Volvo). But if all you have is Softimage, I don't know how to help you.
Here's an example of a car I modeled in Autostudio:
[ 10-22-2001: Message edited by: idjeff ]