On my current ETOU-B plan with PG&E, I'm paying $0.21894 when charging after 9PM. When the switch is made to the EV-A plan, it'll be down to $0.12559(summer)/$0.12866(winter) after 11PM. Jealous of those paying < 5 cents. But, gas is $4.29 around here so I'm still expecting to save more than $3K/year if the early numbers hold up.
I do have solar panels, so since I started driving my M3 this past weekend, I'm still generating more electricity that I'm using. Sure this will change once it gets warm enough where I'm using the AC a lot both in the house and car. Also, I got the solar panels last Fall (when I wasn't expecting to get the M3) and the M3 last December (because I wanted the $7,500 tax credit this year to buy stuff), so I likely don't have enough panels to offset the charging over the course of a year. After a year of driving and charging the M3, I'll see about adding more panels and maybe 2-3 Powerwalls.