[gnicholas]

Unless I downshift using paddles, my ICE will coast forever from 75. My PHEV, on the other hand, will slow down much faster. I want my PHEV to illuminate the brake lights if I'm decelerating above a certain rate, just as you suggest.

It never occurred to me that I might want my ICE to do the same, but I suppose it would be helpful if I'm heading downhill and downshift without touching the brake.

[perilunar]

How will we then be able to tell which drivers are ignorantly riding their brakes all the way down a long hill, versus the drivers using engine braking?

[tristor]

By listening? Engine braking makes noise, which is why it’s banned in some areas.