My office is in an area with lots of really old people. There is a retirement community right across the street. They don't walk to the store. Most of them drive. A few take the shuttle bus that the retirement community provides.

Normal people, able to see well enough to drive, often look one way and walk another in the parking lots around here. People walk right into my pickup truck (not a hybrid) while I am stopped with the motor running waiting for them to get out of my way. It is really amazing. They walk right into a stationary full-size pickup truck, with a V8 motor and an air compressor running, and then seem surprised. (I have air horns, so the compressor runs to top up the air tank each time I start the motor. It actually makes a lot more noise than the motor.)

I usually see them coming. I am sometimes tempted to give them a little toot from the horns before they hit me, so they won't scratch my paint.

I frankly don't think any little noisemaker will help. They won't pay any attention to it.