Break Lights when Engine Breaking

Break Lights when Engine Breaking
Ever find yourself slowing down by taking your foot off the gas or down shifting to let the engine slow you down. You then notice in the rear view mirror the cars behind you quickly catching up. You then apply the break to signal the cars behind you that you are slowing down.
Engine breaking is becoming even more common with the hybrids that use the engine to slow down the car and store the energy into the battery.

I'm suggesting that for hybrids and no-hybrids either use the existing break lights or add an additional light that goes on to signal some threshold of deceleration that occurs even though the breaks have not been applied. Also useful when slowing down on step up hill by taking the foot off the accelerator.