There's an actor called Jack Gordon in both It's a Wonderful Life and It's a Wonderful Afterlife.
In the closing credits presenter Konnie Huq makes a cameo appearance
Gitali/Linda's creepy "psychic" scene during the engagement party (at around 1h 16 mins) is a spoof of the prom scene from the film Carrie (1976).
The background music when Raj is doing his initial investigation is the theme from Tom Selleck's "Magnum PI."