You could download this: https://github.com/hrap1919/qbc
Set up Tautulli and use the notification agent feature. Set up one notification on “Play start” to call a shell script that uses this command to set the alternative speed limits.
Set up a second agent to listen for “Play stop” and set the condition to be “Streams” equal to zero, so when the last active stream ends you reenable full speed.
Edit: Wait someone else posted this and it seems easier and better documented https://github.com/fabricionaweb/qbit-toggle-speed
The cost to maintain the servers to send extremely small packets of data to instruct the car for the entire fleet of cars they sold could be less than $100/m.