The vehicle was marketed first as the Rover 2000 and was a complete "clean sheet" design intended to appeal to a larger number of buyers than earlier models such as the P4 it replaced.

Younger and increasingly affluent professional workers and executives were seeking out cars that were superior to the normal 1.5-litre models in style, design and luxury but which offered more modern driving dynamics than the big three-litre class and lower purchase and running costs than sports saloons such as the Jaguar Mark 2.

Automotive technology had improved significantly in the mid-to-late 1950s, typified by the introduction of cars such as the Citroën DS and Lancia Flavia in Europe and the Chevrolet Corvair in America.

The relatively sharp plastic projections did not meet homologation standards in some export markets (including Germany), however, and so a lens with a smooth top was substituted where the law demanded.

One unique feature of the Rover 2000 was the design of the front suspension system, in which a bell crank (an L-shaped rotating bracket trailing the upper hub carrier joint) conveyed the vertical motion of the wheel to a fore-and-aft-horizontally mounted spring fastened to the rear wall of the engine compartment.

It lacked the Citroën shark nose, which it was planned to introduce later as a drooping bonnet with headlamps in pods and projecting sidelights.

[6] Luggage compartment space was limited due to the complex rear suspension and, in Series II vehicles, the boot mounted battery.

Series II models briefly offered Dunlop Denovo Run-flat tyre, eliminating the need for a spare, though this was not commonly selected and is very unusual on surviving examples.

It had 'square' dimensions where the cylinder bore and stroke were the same (85.7 mm or 3.4 in) to minimise piston speeds and bearing loads, which was very unusual amongst British saloon cars: these tended to have under-square (long stroke) engines, a lingering legacy of the pre-1947 horsepower tax system and the driving conditions encountered on British roads in the pre-motorway era.

The cars varied very slightly in appearance because radio aerials, a heated rear window and a locking fuel cap were optional extras.

[citation needed] Rover later developed a derivative of the engine by fitting twin SU carburettors and a redesigned top end and marketed the revised specification vehicles as the 2000 TC.

Limited availability of the redesigned induction manifold needed for the twin-carburetter engine was given as one reason for restricting the 2000 TC to overseas sales.

A 3-speed Borg Warner 35 automatic was the only transmission until the 1971 addition of a four-speed manual 3500S model, fitted with a modified version of the gearbox used in the 2000/2200.

All variants carried the battery in the boot and had new exterior fixtures such as a plastic front air intake (to replace the alloy version), new bonnet pressings (with V8 blips even for the 4-cylinder-engined cars) and new rear lights.

This was highlighted in August 1975 when Drive, the magazine of the British Automobile Association awarded a trophy to a Rover 3500 as the worst new car in England.

[14] It reported that a Rover 3500 purchased in 1974 had covered 6,000 miles (9,600 kilometres) during its first six months, during which period it had consumed three engines, two gearboxes, two clutch housings and needed a complete new set of electrical cables.

[14] The runner-up prize in this rogue's gallery was awarded to an Austin Allegro with forty faults reported over ten months, and a Triumph Stag came in third.

[14] Further evidence of poor quality control on the 3500 assembly line at the Solihull plant appeared in a report in Autocar magazine in October 1976, surveying the experiences of company car fleet managers with the model, although the report also suggested, apparently wishing to appear even-handed, that at least part of the problem might have arisen from excessively optimistic expectations of the model.

While Triumph enjoyed considerable success with the estate version of their 2000 saloon, Rover seemed happy to leave that sector of the market entirely open to their old rival.

However, Battersea-based coachbuilders FLM Panelcraft picked up Rover's dropped ball and produced their own estate conversion of the P6, called the Estoura.

Although no actual figure for the production of the estate are known, due to a fire that destroyed the company records, amateur investigations by several Rover enthusiasts show a little over 200 cars were known to have been produced.

Crayford's involvement in the project was limited to the interior of the car, and the company had no bearing on the external design of the estate conversion.

This version was called the NADA (North American Dollar Area) model, equipped to a higher standard than UK cars and meeting federal safety and later also emissions requirements.

Inside, depending on the location, the North American 3500S was also equipped with electric windows, power steering and air conditioning, all of which are extremely unusual in UK market P6 cars.

The NADA P6 introduced features which would later appear on the UK Mark II car, including a new instrument cluster and seat piping.

The cars were not popular with American buyers, and a large number ended up being diverted to Continental Europe instead as they were already left-hand drive.

[18] In true British Leyland fashion, several UK cars also ended up with single scoops on their bonnets in an attempt to use up the surplus parts from the now defunct export models.

The company told their US dealers that modifying the P6 to meet new US federal safety and pollution requirements would be prohibitively expensive, while experience elsewhere suggests that the Rover's four-cylinder engine was particularly hard to adapt for reduced octane lead-free fuels without an unacceptable reduction in the car's performance.

A notable factor about the NZMC-built Rover 3500 was that it was exported from New Zealand – 2,400 were shipped to Australia for sale there, in return for CKD kits of the Leyland P76.