(at around 32 mins) Stunt No. 5 involved Phuchit eating a plate of feces, which in reality was a mix of durian, syrup and peanuts.
(at around 19 mins) Thailand's prime minister at the time, Thaksin Shinawatra, is directly referenced in the film--his photo is on the newspaper Phuchit uses to swat a fly.
The film covers one day but actually took about seven months to film.
A short film prequel, 12 Begin (2006), was made as part of the film's pre-release promotional campaign. It was shown in limited screenings at SF Cinema City theaters. A sequel called 14 Beyond (2009 was released in Thailand in 2009.
In 2006, the exchange rate fluctuated between approximately 0.02437 and 0.02570 US Dollars (USD) per Thai Baht (THB). Using the average rate of 0.02503 USD per THB, the 100,000,000 THB prize money for completing all thirteen tasks would have been worth about 2,503,000 USD at the time of the film's release.