A note on boost racing that I posted on the Weekly Race thread.
I talked with some guy in PD ABOUT BOOST. He confirmed that when the boot in the rear becomes too extreme for a trailing driver to cope with, the lead drivers will be "braked" untill ALL cars return to the envelope of the boost algorithims. It is a question of getting everybody back into the bucket w/0 killing the trailing drivers. As lars noted, when dealing with boost in more powerful cars the driving line will provide updated braking information . You still brake later than the beginning of the red zone but it WILL prevent those embarassing Oh Sierra moments when you brake at your "normal" point with 1.25% more boost.