They were all heading toward the exit, and the fleet of cars picking up celebrities was lined up one by one. Generally, celebrities, when making an appearance, choose vans because they are spacious, have room for resting and making up, and also offer a good level of privacy.
These vans aren't cheap either; the cheaper ones also cost several hundred thousand, while the expensive ones start at a million. Unless it's a company car, any celebrity who brings their own vehicle would at least have a van starting at a million.
But even a Mercedes-Benz or a BMW van seemed slightly inferior in front of a row of Rolls-Royce Phantoms.