It's slot cars. They are better now. Some are 4 wheel drive and have strong magnets. So now they hug the track better and don't fly off as much.
And costing upwards of 60 bucks each you don't want the cars to fly around to much.....although thats the fun part.
Good looking bike. Be careful of those fenders, they will crack at the mounts and wad up in the wheel. I take clear Silicone rubber and load it in the space around the bracket, stops the vibration and holds it tight. Have fun, Dave
PS: I was a slot addict as a kid.