Looks like GM is definitely in on this with Lyft: https://blog.lyft.com/posts/expressdrive
Also, apparently Hertz: https://thehub.lyft.com/express-drive-hertz-update/
Program: https://www.lyft.com/expressdrive
This is all I could find on cost for Lyft: https://help.lyft.com/hc/en-us/articles/218196557-Express-Dr...
For Uber, they also partner with Hertz: https://www.hertz.com/rentacar/misc/index.jsp?targetPage=Ube...