Let's consider for a second though. With the size savings of HV wire you now have room for a _lot_ of nice insulation that could last a long time. Arcing would not be a problem if you don't do live disconnects/reconnects. Rain would not be a problem with extra insulation. If arcing does occur this could be detected and power interrupted for safety, and a faulty cable replaced.

10kV is indeed a lot, but say 1kV 600amps or 1.5kV 400amps is much more doable.

High speed satefy mechanisms could mitigate this. Put a grounded pad under the car and cut power if anything flows for more than a microsecond.

I think it's doable