You need at least one car to ride on the guideway. If you're using a slotcar track, you can attach something to the slotcar.
In the pictures above, a small piece of plastic is attached to the slotcar, and the linear array of lights you built from a previous Instructable can then be attached to the plastic piece.
You can begin testing by attaching a single light to the car, to move along in a long exposure photograph.
If you get this far, please click "I made it" and post some pictures and I'll give you some feedback and constructive criticism.
You can learn quite a bit from simply moving light sources along known trajectories. The patterns you generate will help you understand the nature of space and time in the context of Persistence of Exposure.
Then you will be ready to try with the SWIM (Sequential Wave Imprinting Machine) that you built from the previous Instructable.