bwilson4web -
Yes, the context is a lot more complicated than "hybrids are quiet". But what studies are you citing? Does it take into account SUVs as a "percentage of the vehicle population"?
That said, I'm not into the radar stuff and I don't have confidence in auto-braking (yet). It seems like it would be cheaper and easier to have a speaker saying "I am a hybrid, I speak softly and carry a big battery",
. Why not the engine noise of your favorite car? I could have a Cobra one day, chitty-chitty bang-bang another day.
CarloSW2