Algodoo

Not brilliant but it works!
Put blue car on blue lane, controlled with up/down arrow.

Put red car on red lane, controlled with w/s keys

Extra track included to build ur own circuit! i`m sure ur all smart enough to figure out whuch bits to use as you go round, just make a solid red line and a solid blue line all the way round!

once i figure out how to get a figure 8 going i`ll be well happy!