What they came up with was quite the looker. The Mantis XP wears a wedge-shaped fiberglass body, designed to maximize speed down Le Man’s long Mulsanne straight. To do so, the car utilized a long, low nose and a shockingly squat ride height – talk about kissing the cat’s eyes.
It sent Marsh to the market in search of a BRM V12. Unfortunately, it proved too expensive, so the Mantis XP ended up with a Repco V8, supplied by none other than Jack Brabham. Mated to a Hewland DG300 five-speed gearbox, the Australian-built V8 put out more than 300-horsepower.
The car’s Formula 1 parallels didn’t stop there either. Marsh phoned up John Cooper, of the Cooper Car Company, and bought suspension components that saw use on the 1967 T81 Formula 1 cars. However, the car’s chassis remained truly a Marcos staple, thanks to its plywood monocoque architecture. Yup, plywood.
Instead of fielding the car at the 24 Hours of Le Mans, which had been delayed by three months, Marsh swapped out the car’s racing motor for a Buick V8 and registered the Mantis XP to be driven on the UK’s roads. It backfired. British tax collectors demanded Marsh pay an exorbitant amount of ‘purchase tax’ on the vehicle, so Marsh shipped it to the United States.