The cashier and technician, both older and not to be confused with the very helpful and friendly marshalls on the track, were rude and confrontational when I complained that my kart was slower than the others (I started in third and was lapped by half the grid multiple times - and yes, I know how to drive). When I complained they essentially insinuated I was lying to get free laps. (Nice, eh? I was pretty insulted.) Eventually the technician, grumbling and visibly skeptical, said I could try another car - I ended up winning the next race by over half a lap.
***Goes to show you the karts all operate at different speeds, making racing nearly impossible. And they really don't give a shit about that.