Jaguar does not build many cars like the Jaguar XJ13: a 2-door Roadster with 5.0 L DOHC 60 Degree V12, built from 1966 in the decade that gave the world the pony car and the mid-engined supercar. Its designer of record is Malcolm Sayer.
The background
The Jaguar XJ13 is a prototype racing car that was developed by Jaguar Engineering Director William Heynes to compete at Le Mans in the mid 1960s. It never raced, and only one was produced.
The engineering
Under the skin sits 5.0 L DOHC 60 Degree V12. Kerb weight is 998 kg. The gearbox is a 5-speed ZF 5DS/25 manual. The layout matters: the engine sits behind the driver and ahead of the rear axle, which puts the mass in the middle of the car and is why mid-engined cars change direction the way they do. The wheelbase is 2410 mm. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
Where it sits
Where it sits in Jaguar's history is not in doubt: the Jaguar D-Type came before it; the Jaguar XJR-5 followed it; it was built at Coventry, United Kingdom. On a showroom list of its day it stood against the Lamborghini Miura, the Alfa Romeo Spider, the Toyota Corolla. Its Jaguar stablemates include the F-Type and the Vanden Plas.
The money
EPA combined economy is 21 mpg, about $4,450 a year in fuel at the EPA's assumptions. Condition, mileage and specification move any single car a long way from a headline figure.