Go to a guest and change his or her name to the following names to give that guest a personality. If you wish to achieve a desired effect with multiple guests, simple enter the same name but change the names case.

Fast Go-karts: Damon Hill
Faster Go-Karts: Michael Schumacher
Guest pay 2x entrance fee: John Mace
Hunry Guest: Tony Day
Increase Guest Happiness: Melanie Warn.
Photographer Guest: Chris Sawyer
Pick Pocket: Richard Tan
Slower Go-Karts: Mr Bean
Waving Guest: Katie Brayshaw