Beyoncé
Because the Queen is in contract with Pepsi, if you bring a bottle of Coke even near her, it will violate her terms. On set, she usually asks for heavily seasoned, baked chicken legs, breasts, and wings with hot sauce. She also requests that the temperature in her dressing room be set to a toasty 78 degrees at all times.
Christina Aguilera
Aguilera hates to be kept waiting. In order to bypass traffic, she requests a police escort and "under no circumstances are the vehicles to encounter any delay due to traffic." Doesn't she know that sometimes you can't control traffic? I'd hate to see how she reacts to a red light.