The expensive custom built radio controlled car and speedboat proved to be susceptible to signal interference from external sources that wasn't discovered until the production crew took the models out of the workshop and onto location filming. This was another reason why the series never went into production beyond the pilot show and Gerry Anderson instead started developing his next project, SPACE 1999.
Pilot show for a proposed television series that never sold. The mixture of live action and puppetry proved to be extremely hard work to make and edit together and when no broadcaster showed interest in commissioning a series, Gerry Anderson abandoned the concept.
This pilot was filmed on the island of Malta where the production was plagued by bad weather and technical issues. Gerry Anderson was never happy with the final result and apparently quite relieved it was never commissioned into a full series.
Although the series was never commissioned, UK toy manufacturer 'Dinky Toys' were so confident in the project (before the pilot had even been finished) they started working on designing toys based on the vehicles in the pilot. When the show wasn't picked up they redesigned the packaging and colour scheme and the toys were released anyway as generic futuristic vehicles.
The concept of the show came around after NBC in the US were looking for a children's action series after they had seen how popular previous Gerry Anderson shows Thunderbirds and Captain Scarlet had been with audiences. However the production of the pilot was troubled and Anderson himself was unhappy with the final result so he was relieved the show was never picked up by the network.