>>There's a *lot* of discussion of this on rec.autos.makers.honda.  Modern
cars have been shipping with thinner and thinner brake rotors, as a way of
saving weight and improving EPA fuel economy numbers.

Rubbish, I'd say, what they're trying to save is unsprung weight, not
overall weight for fuel consumption
If indeed they are using thinner barke disc, which surprises me greatly!

>I've also heard a theory that it's caused by sitting with your foot on
the brake after heavy braking.  (The theory being that the rotor cools
differently where it's clamped by the caliper.)  Personally, the only
warped rotor I've had was done in by a draggy caliper, so heating was
definately the culprit there.

This can definitely warp the discs, keeping foot on brake after a high speed
braking session, or multiples thereof, don't forget they're glowing red
after a a few fast roundabouts (90 - 40), 90 - 40 and then 90>0 in a 1 ton
vehicle (and if you have roundabouts there.)