(at around 1h) The line in the film where Jonny Lee Miller playing Simon Sheppard says, "Never, ever fuck with an antiques dealer," was a line the actor would say on set as a joke. The director liked it and incorporated it into the scene.
Dracula says, "I don't drink... coffee," in one scene. This is a spoof of "I never drink... wine" from Dracula (1931).
The name of Van Helsing's antique business, "Carfax Abbey" is also the name of house Dracula moves into in Bram Stoker's book "Dracula".
Script doctor Scott Derrickson told the story of how he got the job working on this film. Harvey Weinstein called him, saying, "I just bought this script, called, 'Dracula 2000'." Derrickson replied, "Oh, yeah? Is it good?" Weinstein replied, "It stinks!" Derrickson asked, "So why did you buy it?", and Weinstein replied "Because it's called, 'Dracula 2000'." Derrickson did the re-write, which Weinstein discarded. Ehren Kruger did the next rewrite.
(at around 37 mins) When Lucy (Vitamin C) is talking to Mary in the record store, she is standing right in front of a shelf that has her CD on it.