This car is really cool, I'm not going to argue against that for a single second. But your suggestion of a "practical track day car" is missing the fact that there are two things making this crazy fast: huge downforce and ridiculously low weight. It weighs less than half of what a Nissan Leaf does, has a single seat, no storage for anything, no aircon etc. etc.

If you tried to make it approach the practicality of a Nissan Leaf while still being performant, you would not just need more space and weight for the practicality, but you'd end up tripling the weight since you would also need a much bigger battery pack to keep the runtime at the current ~30 minutes on a track, bigger motors to keep the acceleration high when you're dragging that weight, much wider tyres to enable cornering at these speeds, etc. etc. Then you're no longer killing hypercars but rather maybe matching a Bugatti Veyron, and you might as well just go for standard aero so you don't have the 120 dB (!!) fan noise inside the cabin.