Improve traction control and regen to better handle icy road conditions where max regen may cause the back-end to slide out.
From what I’ve heard, regen on icy roads can cause the car to become unstable and let the back end break out (like when using the handbrake on a regular old car). People are advised to only use “low” regen to avoid this. I thought this was very strange: why can’t traction control limit regen when the back starts to break out? Did Tesla just buy a standard ESP package for normal cars that do not know how to handle regen? So my feature suggestion is reprogramming the traction control so that it can handle problems with regen. Electronic stability should work in any circumstances, including when using regen. If the car can release the brakes and even brake individual wheels, shutting off regen to stabilize the car should be easy.
A software update in 2015 improved traction control in icy conditions.
According to a post on the teslamotors forums, the issue seems to have been fixed in a software update. People reported no longer having any issues with normal regen on icy roads, while they did use to have problems before. Selecting "Low" appears to no longer be necessary.
In my (so far somewhat limited) experience having full regen on slippery/snowy roads may cause the car to be a bit wobbly down hills, but I have so far not had the experience of "handbraking". It does feel very loose, though, so on wintery conditions I prefer lower regen.