Hello,

Cars modelling is a challenging topic whatever the method you pick.

Maybe the advantage with Blender is that you might find a complete tutorial to go along that will teach you all the steps. That said most of those tutorial as considered "advanced" and probably assume you have basic knowledge with Blender navigation and subdivision modelling in general. If it's you first step I would probably try to find an easier subject, like a mouse, any kind of relative 'smooth / curved" object.

If you want to stay in the Nurbs land, you probably may need to check one of those tutorial made for Rhino ... and solve all the missing functions by finding workaround. For the initial curves sketching there is nothing as easy as MoI imho (but even for that step some tutorial will also show advance feature like curve deviation analysis). Patching/surfacing those curves require however a lot of work and experience. That's probably where Xnurbs can help a lot, as it's so permissive while producing really pleasant surfaces with good continuity.

If you are more in the conceptual design without really precise blue print, you might wanna try an hybrid approach, by designing the initial rough shape using subdivision modelling, convert that cage mesh into Nurbs using MoI Sub-D import and finish the details / trimming / and all that jazz in MoI. But even with that method you need to get some experience with subdivision modeling, edge loop (support), topology ... so again starting with simpler model is a first step before poly "knitting" a complete car body.