Just use a Model S with the newest battery-cell from panasonic! I guess it's around 4kv or more, and fill the battery-pack completely (I understand from people on the forum that the 85kw pack does not use all the space for cells it is able to contain) Of what I understood on this forum, it is suggested the battery-cells for the 85kw battery are around 3.4kv. I guess we are near the 500 mile range for the Model S then when using those new cells!
Supercharge every time you change tires, and it looks more and more plausible to race!
Or am I dreaming?