Audi has been shipping electric compressor for 5 years now. They are prone to failures and they are on second revision now.

https://en.wikipedia.org/wiki/List_of_Volkswagen_Group_diese...

That's a different design; Audi uses a separate electric supercharger to fill in boost while waiting for its conventional turbochargers to spool up. Porsche is using a motor/generator built in to a turbocharger to spool it faster, and to recover energy at maximum boost.