the tree is a vital key in drag racing, the driver response to the light turning green while not going before then is what wins alot of drag races.
I would like to see Gran turismo incorporate a true straight level say 2 mile drag strip that could be set to 1/4, 1/2, mile, or full length for top speed races(similiar to the Texas Mile) with a tree, but one that allows you to leave before the light and get dq'd for it.
Utilizing the ingame lap timer at the tunnel is ok but I know for a fact that the way my viper is set up I can let off the brake a full half second early and I won't leave till the right time, but I leave the line very quickly. This quickly degenerates into everybody jumpin the clock earlier and earlier which makes the races meaningless