For the first film, three DeLorean automobiles were purchased for modification into the now-famous time machine. An additional three vehicles were purchased for the two sequels, and a full-sized fiberglass DeLorean replica was built for the flying scenes in Back to the Future Part II.
The time machine was designed Ron Cobb, Andrew Probert, and Michael Scheffe.
Kevin Pike's special effects company Filmtrix built the first three DeLorean time machines in just ten weeks.
Many of the props on the time machines were electrical industrial surplus. However, two iconic props were off-the-shelf items: the nuclear reactor was made from a Dodge Polaris hubcap, and the "Mr. Fusion" unit was created from a Krups coffee grinder.
During filming when the time machine's doors were iced-down, the doors would suddenly fall and hit the actors in the head. Special effects crews had to heat the gullwing door struts with hair dryers between takes in order to keep the doors up.