I know in the spy movies it always looks really cool when the operative goes from a maid's uniform to a slinky, sexy, ballgown in the amount of time it takes an elevator to climb three floors. Well, I don't know how it is for TV spies, but I can tell you that even with Velcro, the art of the quick change is one that must take a lot of practice (not to mention better lighting than one is likely to find in a tunnel that was once part of the underground railroad).
Ally Carter (2010). “Gallagher Girls: I'd Tell You I Love You, But Then I'd Have To Kill You”, p.107, Hachette UK