Eileen Brennan, who played Stan Fields' mother, was a year younger than William Shatner, who played Stan. He was born in 1931, she was born in 1932.
Miss Detective (2000) was supposed to include a storyline in which Gracie Hart's mother was killed in the line of duty. The storyline was included in this movie.
During the film's promotion, Sandra Bullock joked that this wasn't a sequel but the second half of one big movie, and that those who could show their receipt for Miss Detective (2000) could go in for free. She later admitted that she was very reluctant to do sequels, given that she did two sequels in her life (Speed 2 - Senza limiti (1997) and this film), and she considers both of them "horrible".
A Miss Detective (2000) poster can be seen in the background, at Las Vegas McCarran airport, during the scene where Gracie is supposed to be flying back to New York City.