Hey, n00b here.
I got a ZZ and I made a track. Thought I'd share how I did it. It takes about 40 minutes to measure it, depending upon how much of a perfectionist you are, and 5 minutes to make. Oh, and the cost is about $6.
I bought weather stripping. The type I got is 3/4" wide and 1/2" high and cost $3 for 10' of it. They make smaller and cheaper stuff, and lower stripping that's made of rubber instead of foam may just be better. I had a piece of 1/4" plywood for the base, but cardboard would probably work as well. I just made a design, and measured it out, and stuck on the weather strip.
Done.
Here's some info about it:
-If your car touches the wall, your car stops instantly

. But, because the stuff is foam, there is absolutely no damage.
-I made my lanes 8" wide. It's too narrow. A hairpin turn requires at least 10" lanes if you don't want to hit walls. Yes, 8 is possible, even in an S curve, but unrealistic and not very fun. 8" lanes with foam walls make the "control" motor fun because you'd be lucky to do more than a lap without touching a wall with a faster rig.
-The weather stripping comes with an adhesive side that sticks on contact. This makes for fast set up. It gets stickier over time, so if you let it set it gets more permanent, but it doesn't ever seem to get to the point where you can't pull it up to redesign the track, so redesign is fast and easy.
So, if you need a quick technical track, this is easy and fast. But again, the reason that it's technical is that if you touch the walls, you come to a dead stop. I did find that if you hit the wall head on and throw it in reverse at the right time, you can get a real fast reverse.
I didn't see a track forum, so I apologize in that special newbie way if this is in the wrong spot.