Daniel's license plate number is ERIN G BRGH, an abbreviation for Erin Go Bragh which is a popular Gaelic slogan meaning "Ireland Forever".
License plate number of Colleen's blue VW (new-style) Beetle is COL BUG.
The hit-man refers to a "Senator Dove" who has died... this is the same person whom Mickey, a hit-man, talked about killing in Chain of Fools (2000), also written by Bix Skahill.
Harry Connick Jr sings the song "Danny Boy" in the first film he was in, 'Memphis Belle', and he also sings it in this movie.