"It's more impressive than a purpose built shifter kart. "
It's not even close to a shifter kart. Shifter karts have no suspension, relatively low power, no downforce, and are bought, not made.
"Pretty hard not to suck at driving that kart.
"
AM cars are rediculously hard to drive. Again: if that guy drove your Contour, and you drove that beast, he would win. Plus, it's much harder to make something like that handle well than a street car. With my car I have to worry about alignment, spring rates, swaybar, and damping. He has way, way more to deal with: there's no design factor that he didn't have to engineer carefully to make it as fast as possible.
