Hope y'all don't mind me breaking this discussion out from the California Owners thread into its own topic.
pbui, you've obviously piqued our interest, and especially mine as I've been advocating a paddle for regen even before I installed one on my Gen1 Insight (on the now-defunct Aptera forum).
On your Volt, is the implementation the same as on the Cadillac ELR?
On the Cadillac ELR, the amount of regen was (is?) proportional to the amount of time the paddle is pulled back, gradually increasing the longer you held the paddle (I never tried it, but was told that's how it worked).
On my Gen1 Honda Insight with my MIMA modification, the amount of regen was proportional to the distance the joystick (paddle) was pulled, the more the joystick was deflected, the higher the regen. On the Insight I also had the opposite benefit: pushing the joystick gave me pure electric acceleration; in effect, I had an electric supercharger to at my fingertips to supplement the 1000cc gas engine and supposedly higher torque than the stock system. Sadly, this car was totalled by a drunk driver rear-ending. I pulled out and have the entire MIMA system in a box, but not the priority to install it into my second Gen1 Insight.
pbui, with your long downhill grade into Los Gatos from home, I bet the Volt's regen stops working at some point as its battery gets filled.