Just listen for the sound of smug self-satisfaction

Seems to me these folks are trying to make their problem my problem. And isn't this just an extension of an existing problem the blind must have with bicyclists? How about instead of making me play the Mister Softee theme wherever I go in my motorized egg, blind pedestrians have to wear (or make their service animals wear?) big flashing signs that say "Watch Out: I'm Blind And I Can't Hear Your Hybrid!"

Or, to be a bit less snarky, how about just starting off with an education campaign? You could include something in the owner's manuals of hybrids about watching out for folks with service animals who can't hear your car. I'm a motorcyclist, and as with all riders, have been variously threatened by cars that simply did not see me because they weren't looking for a motorcycle. One solution which I believe has done some good in that context is an education campaign with bumper stickers that say, essentially, "Watch For Motorcyclists" just to increase awareness.

But just for fun, I'd love to hear suggestions in the comments about what the appropriate theme music should be for one's too-quiet Prius. I'll start with what I'd use: The Imperial March that they'd always play for Darth Vader. But only if the car was black.