Toyota is not very open about Prius adapters. You won't be able to purchase them at dealers. You can go to Toyota Parts Kyohan:No worries, this is good info. I'm still in back-and-forth with Tesla about the answer to #2...will update the group when I find out more.
As for 1, do you have a link for the Prius PHV adapter? I found mostly 3-prong adapters or other higher-voltage ones, but didn't see any 2-prong adapters.
Thanks again!
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for pricing. It comes with 3 prong but you can convert 3 prong to 2 prong by an adapter, and Toyota's charger still worked without ground. But my experience was for previous version so you need to test before purchasing.