there is a MT block which turns on the cars lights when triggered. I believe its called "CarLights" give that a try.

There is a bigger problem, actually:

You can VALIDATE your track (set an author time) before lights/shadows are calculated. Since the calculation of shadows can cause some portions of the track to become too bright or too dark, this gives the author a potential to create basically "unbeatable" map (or a map where you cannot play without crashing), while the author could finish that map without problems, because when "he" was playing, the over-bright or over-dark parts were not there.

I'm curious whether someone will actually abuse this fact...

Alcator says:
I'm curious whether someone will actually abuse this fact...

Please don't give them ideas...

Sure, because every author's goal is to create a track where you crash because you can't see the road. Evil geniuses could use this strategy in order to... uh...

Alcator says:
There is a bigger problem, actually:

You can VALIDATE your track (set an author time) before lights/shadows are calculated. Since the calculation of shadows can cause some portions of the track to become too bright or too dark, this gives the author a potential to create basically "unbeatable" map (or a map where you cannot play without crashing), while the author could finish that map without problems, because when "he" was playing, the over-bright or over-dark parts were not there.

I'm curious whether someone will actually abuse this fact...

You can also turn the lightmaps totally off. However, that function seems to be broken XD.