This was important not only because I need to have my own vehicle in the finished game, but also for getting used to setting up a vehicle in the editor, which is no quick task.
As before, this tutorial has been so useful in learning a basic step-by-step setup of wheeled vehicles in the UDK:

After a little tweaking and some initial hiccups, i'm happy to say that the vehicle worked - more or less. Compiling the code each time seems to bring up slight issues that shouldn't be possible - exiting the vehicle will crash the UDK on some occasions, but not on others (the code itself remains unchanged). Still, I have a very, very basic test vehicle running around in-game which will allow me to do some course planning and testing... once i've scaled it down a bit.
Here is the basic animTree for the test steamcar:

And here's a screengrab of the (very) basic custom vehicle in the editor.

Here's hoping some real progress can be made from now on!