According to John Carpenter in the DVD Commentary, Carter Wong, who plays Thunder, actually worked as a martial arts instructor with the Hong Kong Police.
In the wedding Scene where LoPan is putting the Needle of Love in Miao Yin, James Hong actually jabbed Suzee Pai too hard. You can see her flinch as he puts it in her.
Jackie Chan was considered for the role of Wang Chi but producer Lawrence Gordon was highly against it as Chan had lacked a box office draw in America at that time. But John Carpenter wanted Chan after seeing "Police Story"(1985), Chan declined to concentrate on his career in Hong Kong & decided that he'd return to hollywood when he felt he was ready to which wouldn't do until "Rumble In The Bronx" (1994) the role was later given to Dennis Dun.
When Jack, Wang et al exit the Wing Kong Import/Export Exchange Company, Uncle Choo is waiting outside in a yellow bus. Wing Kong security then open fire on the bus as it drives away. However, as the bus turns a corner seconds later you can see that there aren't any bullet holes or broken windows on the side of the bus they were shooting.
In the deleted/extended scenes on the DVD, as Jack's truck pushes the car into the water, one shot shows the car driver's window is open. The next shot shows it is closed.
When Jack Burton is explaining what happened in the alley, he mentions that Lo Pan had "light coming out of his mouth". However, Jack could not have seen this, as he was already temporarily blinded by the light from Lo Pan's eyes, and had his hands over his eyes by the time the light came out of Lo Pan's mouth.
Lo Pan: [Yells at Wang in Chinese after growing frustrated with Jack's dismissive attitude]
Mr. Burton, if you have an influence over your youthful friend, you better exert it now. Otherwise, I will have you both brought out to the hell where people are skinned alive it's that simple, understand?
Upon seeing that Lo-Pan's has been killed, out of sadness and anger, he either lost temper and uncontrollably exploded, or allowed himself to explode on purpose in order to commit suicide.
Q
What happened to Jack Burton at the end of the movie?
A
It is unknown and totally up for personal opinion. Some believe that he was attacked and killed by the beast hitching a ride on his truck, whereas others are confident that Jack would have defeated the creature and continued on his journey. At one point, a sequel was announced, but later scrapped, staring Kurt Russell. This would suggest that Jack Burton was alive and lived to fight another day.
Q
What are the differences between the British BBFC 15 VHS and the Uncensored Version?
A
The Theatrical Version lacks the Kurt Russel comment "Fuck it!". The later released VHS contains this comment but lacks some other footage of the turf war between the two clans. The DVD and Blu-ray are uncut. A detailed comparison between both versions with pictures can be found here.