..

+1 good original (OMG) idea mate.

And from me

+1

Would be great for movie makers and watching replays in general.

watch the unofficial addons section. there is a tool out there already which is doing exactly what you want, and even switches to the "action" on track. and you even can select several cars which run in a pack, so the tool tries to focus on those cars.

its called LFS TV Director and is made by Sören Scharf
LFS TV Director, Release 0.2 - Live for Speed
http://www.lfsforum.net/showthread.php?t=14147