Also called the XNR 500, the car is an open roadster with some asymmetric features, and was proposed as a sporty addition to the Plymouth model lineup, and as competition for the Chevrolet Corvette.

[9] Later the car was called the Asymmetrica, and later still renamed "XNR", a disemvoweled, pseudo-acronym of the designer's own last name.

[10][11] The shape of the XNR was influenced by a Studebaker Indianapolis race car that Exner owned, as well as by the later asymmetrical Watson Indy Roadster, and the Jaguar D-Type.

[8][14] Later, after being fitted with a fiberglass nosecone fabricated by Dick Burke and receiving additional engine modifications, the car reached a top speed of 153 mph (246 km/h).

[20] After being returned to Ghia, the XNR was purchased by a Swiss buyer, who later sold it to Mohammad Reza Pahlavi, the Shah of Iran.

[2][22] It was sold again in the early 1970s to a man in Lebanon who kept it in underground storage until Karim Edde found the car during the Lebanese Civil War of 1975–1991 and recognized it.

[2] In August of the same year the XNR won the Gran Turismo Trophy at the Pebble Beach Concours d'Elegance.

[27][28] Apart from the Hyper Pak kit, the engine in the XNR is distinguished by being one of just twelve Slant-6s built to "NASCAR" specifications, which included other upgrades.

[2][26][19][14] It is thus related to the engines that powered Slant-6 Valiants to the first seven positions in the inaugural Cannonball Compact Car Division NASCAR race held in January 1960 at Daytona.

[19] In the front, quad headlamps are mounted in a perforated aluminum grille with a chrome border that serves as a bumper.

[38] Like the XNR, the Asimmetrica is built on a Valiant chassis, and is powered by a Slant-6 engine with the Hyper Pak performance package.

[37][36] In March 1962, a related hardtop version, called the Coupé St. Régis, was shown alongside the Asimmetrica at the Geneva Auto show.

[36] It was later sold by Rob de la Rive Box and Roger Meyer to the Blackhawk Collection, where it underwent an extensive restoration lasting a full year, after which it was shown at the 1990 Pebble Beach Concours d'Elegance.

[40] An Asimmetrica was sold at RM Sotheby's 2018 Monterey Car Week auction for $335,000 (inclusive of applicable buyer's fee).

[36] The chassis number of this car was 1102224086, indicating that it began life as a Valiant V100 four-door sedan with a basic LG engine making 101 hp (75.3 kW), and was built in 1960 at what was then Chrysler's Hamtramck assembly plant.