[Stiglr]

Well, at least for the Batcar, looks like you've got some good 3-view drawings to work from.

With the Segway, I don't imagine it'll be too hard to guestimate dimenions and proportions on most of the items that make it up.

But, overall, you need to grasp the fundmentals of modelling before you create ANYTHING. Objects, surfaces, vertices, modifying objects at all levels, using the automatic features to make items more precise, beveling, etc., etc., etc.

I'm sure if you look around the web, you'll find some basic car tutorials that will help you with the Batcar and the spaceship, for that matter.