My final solution I installed today was a programmable buzzer, programmed for a marimba sound.
The item:
https://www.amazon.com/gp/product/B0058M0TN8
The software (for Windows):
http://www.puiaudio.com/resources-software.aspx
The sound:
https://freesound.org/people/pogmothoin/sounds/401722/
Trim, amplify, and noise reduce with Audacity:
https://www.audacityteam.org
What the final installed thing sounds like:
https://youtu.be/jh9nNqk7hZs
I attached it to pigtails that plug into the cluster feed and ignition unfused. Used zip ties to attach it under the dash.
EDIT: the programmable buzzer is now discontinued, and no longer available at Amazon and not available from other sources that previously sold it, such as Digikey and Mouser. The part number is API-4260-LW150-R. Possible sources:
https://octopart.com/api-4260-lw150-...audio-20059436
https://www.onlinecomponents.com/pui...-50562394.html
https://www.infinite-electronic.com/...0-LW150-R.aspx
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