The SPV was designed by special effects director Derek Meddings based on a brief description given in the Andersons' original script for the first episode, which specified only that the SPV was a high-speed armoured vehicle with reversed seating (and therefore no windscreen), running on a removable "lightweight power unit". Noting that the occupants faced backward and viewed the road through a TV monitor, Meddings said that "all [this] meant to me was that I could design the vehicle without windows." For added realism, these were replaced with grilles and air vents.
To fulfil his vision of a "menacing, shark-like" assault vehicle, Meddings added a tail fin to the design.
Several filming models were built. They were made of either balsa or hardwood in a range of scales, the largest being long.
Depiction
Spectrum's main armoured land vehicle, the SPV is an amphibious, all-terrain machine that can be driven in extreme environments as well as in cities. It is long and has a maximum speed of either on land. Andrew Blair of website Den of Geek calls the SPV "clearly the best vehicle" in Captain Scarlet. Comparing it to "a tank driven at ludicrous speeds, while facing backwards and located in secret garages around the world", he argues that the vehicle represents "probably the fastest transformation from covert to ridiculously unsubtle that fiction has ever seen." Tat Wood of TV Zone magazine questions Spectrum's logic in keeping its SPVs hidden until they are needed ("inside caravans, gasometers, tubes of Pringles or wherever") given that they are "then abandoned on the road".
The rear-facing system is praised by commentators Jim Sangster and Paul Condon, who credit the feature as an innovative "work of genius". Drawing a parallel between Anderson's comments on aircraft design and the Paul Klee monoprint Angelus Novus, Mark Bould of the University of the West of England argues that the system is "full of metaphorical potential" in that it represents Anderson "[promulgating] a naive vision of progress while reinforcing the status quo. Consequently, while the SPV driver [...] might be oriented like the angel of history, he is incapable of seeing what lies behind its forward thrust. Not for him the catastrophe accumulating in his wake; just the deceptively uncluttered road ahead. His [monitor] screen screens: it shows and it obscures. And in such an echo chamber, as Benjamin's fifth thesis notes, 'every image of the past that is not recognised by the present as one of its own concerns, threatens to disappear irretrievably.'"
The SPV's curved front bumper inspired the rounded edges of LaCie's "Rugged" external hard drive, designed by Neil Poulton.
In 2022, YouTuber Tom Scott published a video in which he and a tech company build a go-kart with backwards-facing driver and passenger seats, similar to the SPV. Motorsport Network reported that the experiment had been a success: "It's a little tricky for the mind, especially at higher speeds, but everything works as it should. Does it make any sense? No, not all. But is it fun? A hundred percent."
In a preview of the Polestar 4, Andrew English of The Daily Telegraph compared the car's lack of a rear window in favour of an external camera system to an SPV driver's reliance on a video monitor while seated backwards.
Toys and model kits
Several toys and miniature models of the SPV have been released. These include a 1960s friction-drive toy by Century 21 Toys and die-cast models by Dinky, as well as newer versions by Corgi, Vivid Imaginations and Product Enterprise. Japanese company Imai released a model kit version in 1993.
Action features on the Dinky model included a sliding driver's seat containing a Captain Scarlet figurine, as well as a spring-operated missile. The latter was fired by squeezing the front sets of wheels, avoiding the need for what Century 21 considered to be "ugly-looking buttons". According to website Television Heaven, the SPV "was the toy to have in the early 1970s", and featured "almost as many gadgets and working parts as the ever-popular original Corgi James Bond Aston Martin DB5." Corgi released an updated version in 2024.
In 2025, Scalextric announced its release of a 1:32 scale slot car racing version.
The Rhino
In the animated remake New Captain Scarlet (2005), the SPV is replaced by the Spectrum Rhino.