In fact I have owned two of them, the first one (the red one, no better photograph at the moment) was about 30 years ago, a Princess 2200HLS automatic. This had a 3-speed automatic and all the luxury you could want (especially as a student). I bought it in less than half an hour from a fellow student, who had to make a lot of long drives, and for that this car was not particularly suited. Having the Automatic it used about 7 litres/km.... That same student later in life ended up having owned a total of 17 Princesses...

The second one which I still own, the white one, is also a 2200HLS, though it is a manual four-speed. This is a 1976 model, which however was not registered that year, but in 1977. The first owner had it painted white, and brought it to Torcars in the UK, who converted it to a hatchback. A feature which it should have had from the beginning, but the intelligent people at BMC were afraid it would steal market away from the Maxi, so the car had just a small boot below the large rear glass.

The radical Wedge design of the body was by Harris Mann, and in my opinion still one of the best looking saloons of all times. Especially the way the line of the car drops down at the front door in a slight curve, to return to a climbing line from the rear door.

Technically especially the Hydragas suspension was a unique and innovative feature, not solely used on the Princess though. Invented by British automotive engineer Alex Moulton, Hydragas is an evolution of the previous Hydrolastic system. Manufactured under licence by BTR AVS under the Dunlop brand at the historic Holbrook lane site. It was first introduced in 1973 in the Austin Allegro and was later fitted to the 1975 Princess and its successor, the 1982 Austin Ambassador. Both systems attempt to address the ride-handling compromise of car suspension by interconnecting the suspension of the front and rear of the car in some way. Hydragas attempted to perform the same function and advantages as the hydropneumatic system developed by Citroën, but without its attendant complexity.

The heart of the system is the displacer units, which are pressurised spheres containing nitrogen gas. These replace the conventional steel springs of a regular suspension design. The means for pressurising the gas in the displacers is done by pre-pressurising a hydraulic fluid, and then connecting the displacer to its neighbour on the other axle. This is unlike the Citroën system, which uses hydraulic fluid continuously pressurised by an engine-driven pump and regulated by a central pressure vessel.

Added to this is of course the very smooth 2226cc straight-six, which drives the front wheels through either a manual 4-speed, or an automatic Borg-Warner 3-speed gearbox. Especially the interior is very luxurious in this top of the line 2200HLS model, with foldable armrest on the front seats and luxurious upholstery.

History
The Princess is a large family car which was produced in the United Kingdom by the Austin-Morris division of British Leyland from 1975 until 1981 (1982 in New Zealand). The car inherited a front-wheel drive / transverse engine configuration from its predecessor, the Austin/Morris 1800 range. This was still unusual in Europe for family cars of this type and gave the Princess a cabin space advantage when compared with similarly sized cars from competing manufacturers.

The car, which had the design code ADO71, was originally marketed as the Austin / Morris / Wolseley 18–22 series. Ahead of the October 1975 London Motor Show the range was rebranded "Princess". This was effectively a new marque created by British Leyland, although the "Princess" name had previously been used for the Austin Princess limousine from 1947 to 1956, and the Vanden Plas Princess. The Princess is often referred to, incorrectly, as the Austin Princess. Although this name was not used in the UK market, it was used in New Zealand. The car was later revamped as the Austin Ambassador, a hatchback, which was produced from 1981 until 1984 and only available in Britain and Ireland.

Princess sales, although initially strong, were tailing off by the end of the 1970s. Some of its competitors had gained a fifth-door as a hatchback which the Princess lacked (though Harris Mann originally designed the car with a hatch) and the large family car sector fell victim to a poor economic climate further compounded by the OPEC oil crisis. The Princess was somewhere between the Ford Cortina and Ford Granada in terms of size, being designed to compete with more expensive versions of the Cortina as well as entry-level versions of the Granada. British Leyland restyled the Princess with a boot so that it would not compete with their existing SD1 and Maxi designs.

Total production amounted to 224,942 units, with most examples scrapped by the 1990s. But not all!

Other cars with transverse mounted straight-six engines
Apart from the Princess, and it's predecessor the Austin Glider there was the Australian Austin Kimberley, which however had the same drivetrain as the Princess

After that there has been the Suzuki Verona, which I believe was never sold in Europe? See: www.roadandtrack.com/new-cars/first-drives/reviews/a9946/suzuki-verona/ a car which apparently was made by Daewoo, and was also in some countries sold as a Daewoo. It also had a relativey small 2.5 liter 6-cylinder engine.
One which I had never heard of having this engine and drivetrain layout, was the Volvo S80.