Matthias Hues, who played the film's alien bad guy, performed all of his own stunts because there were no doubles who could match his size (Hues is 6-foot-5).
The shopping center where Caine pursues a stolen Houston Police squad car commandeered by the villain is the former Park Shops Shopping Mall originally built in 1985 in the east end of Downtown Houston. The Park Shops was renamed Houston Center in late 2003 right after the Toyota Center and Hilton Americas Hotel was completed, along with the expansion of the George R. Brown Convention Center.
When the White Boy infiltrates the police station he flame cuts through an iron bar grid which is embedded in the walls. When he's done the grid falls off in one piece, undamaged, with no bars left in the wall.