Both female leads are supporting actress or "nang'rai" who fall for cops.
In Nang Rai Sai Lab, the female lead goes to work with the cops on their case, while here the female lead tries to find an answer to her own personal mystery.
Both have to do with romance with or between celebrities. Differences being that 'Nang Rai Sai Lab' is a little darker and contains a lot of action, compared to the light and fluffy 'Wannueng Jaa Pben Superstar.'