I think your best bet would be to try a much simpler track first. This is an example of a small track we put together that's actually quite fun for it's size and relative simpleness.
We (Raudi1 and I) keep our tracks very wide for a more realistic, modern look... and we keep a lot of run off space so that a person that goes off track is both penalized more and also has room to get the car back onto the track. You can see my post that I just made here:
http://www.magracingforum.com/viewtopic ... 1377#p1377
That's an 8x4 board with 2 lanes on the track. Again, you easily could pack more into this space, and for sure you could add even more by making it a twin level... The things to keep in mind the most are:
1. These things don't climb steep hills as their tires are very slick by design. This gives them the advantage of handling more like a real car, but also makes climbs more difficult. There are numerous other posts about climbing angle and stuff on the board.
2. The cars (in my opinion) really shine more when they have room to run off track and you can recover. If the whole track is so thin that going off means you're blocking the whole track, it's hard to pass because if the leader does make a mistake they end up just blocking you. Also if there's a rail around the outside that keeps the car from going off, the fastest way around the track would be to just floor it and let the guard rail direct the car.
As I say, the width of the track and area for run-off is a personal choice. Many people seem to be ok with thinner tracks, especially if it's just you racing. I think the flaws show up when you have more than one person trying to race, and cars start blocking the track making passing a chore.