If you want something close to a "real driving game" by which I mean one that has some form of accurate driving physics, gravity, friction, mass, force etc, then you are going to need to use some kind of Physics SDK with the DarkGDK(or alternatively design and develop your own), there are a number of them that you can find for free or at low cost around the net, however TGC also sell a great DarkGDK plugin called DarkPhysics(uses the Ageiea PhysX SDK), which is the ideal starting point for learning how to use a physics engine with DarkGDK(it also includes a fully working, albiet very basic, driving demo - car model, jumps, turbo boost and all) and from a programming point of view.
NOTE: It is not nessecary to use a Physics Engine to make a driving
game or any game, just my personal preference. It is completely possible to just use the native DarkGDK functions to emulate things like gravity, friction, force and mass in a driving game(although the mathematics would be complex), or leave them out and make something with more of an "arcade" feel...
To be able to use DarkGDK at all though, the first thing you are going to need to do is learn/re-learn Microsoft's Visual C++ 2008 implementation. Without that knowledge, trying to actually create anything with DarkGDK would be anywhere from very difficult to almost impossible.
Once you have a basic grasp of C++ programming(there are a number of web-sites and/or books that you can read/obtain either free or at low cost on the internet), the next thing to do would be to go through the Tutorials and Samples that come packaged with the DarkGDK when you download and install it, these provide a very good starting point for most things, what you cant find in the samples, you can find here in the forums, many people contribute their tips and tricks in these forums, searching for the things you are looking for using a few different search terms usually gets you what you are after, if its here. Also, sometimes the examples/samples/tutorials are demonstrating more than just the concept that they are titled with... for instance, the Sample that demonstrates the "Lights" in DarkGDK(a statue in a room with some lights orbiting around it, you can change which ones are on/off to change the look) is not ONLY demonstrating lights, the other aspects of that code include how to make an object "orbit" around another(lights around statue), how to accept user input and change the state of an entity based on that user input(lights changing when keys pressed), and also how to move the camera smoothly around an object(the camera itself moves in the demo, orbiting the statue in the opposite direction as to that of the lights) which could be useful for cut-scenes or slow-motion scenes showing actions etc, that particular sample also demonstrates some other very basic GDK concepts, like loading 3D objects and placing them in the 3D-world, displaying text on the screen etc...
If it ain't broke.... DONT FIX IT !!!