Finally, a train that (somewhat) works!...although it's not exactly the fastest thing on the planet. This has given me some ideas for future projects (like Hot Wheels style tracks and roller coasters).
The track itself was painstakingly put together using the circle and sphere tools made by Tajin on the Rawbots forums, so credit to him :D
The most difficult part of this was putting the track together and not getting the train/cart onto the track. The problem now is that the track seems to destroy your CPU.