Okay, first of all - the speed display on the dashcam is very lagged and not something reliable to look at when speeds are changing quickly. It shows me stopped yet doing 25mph at the beginning of the video, it also seems to indicate I was doing 47mph just prior to impact. In reality I was probably doing 5mph, 10 tops when impact occured, I did brake as hard as I could (how about those antilocks? no tire lockup at all) The damage to both cars is minor and I'm guessing if I was going near 47 on impact I'd have thrown that VW quite a ways, airbags would have deployed, etc.
Admittedly, I accelerate fast.. it's one of my favorite things to do in the Tesla, and I'm sure I got up close to 50.. however when I saw that car slowing and signaling I let off the throttle, and at some point I assumed the car was waiting for me to go by so I kept going - by this time I would say very close to the 40 limit - until they started coming over - at which point I braked as hard as I could.
I'm not sure what I should have done there, stopped in the middle of the street as the other car was because they were signalling? As far as I know a signal provides intent, but in no way grants right of way in any situation. At the end of the day, I am wondering what law/vehicle code I was in violation of to be found 20% at fault here. I know of none.