[3] Known to Vauxhall as their C-10, three specially prepared cars were entered in the 1200 mile (1900 km) long 1910 Motor Trials named in honour of Prince Henry of Prussia.

The Prince Henry was a higher tuned version of the Vauxhall 20 hp that had been designed in the winter of 1907-08 by then draughtsman Laurence Pomeroy (1883–1941) when the company's chief engineer F. W. Hodges was away on holiday.

Both Austro-Daimler and Vauxhall offered for sale replicas of their Prince Henry models at the 1911 Olympia Motor Show[4] In 1913 the engine capacity was increased to 3969 cc and the internal designation changed to C. Production continued until 1915.

[1] This 1914 car described below was very familiar to the writer who was a colleague and a close friend of its owner, Laurence Pomeroy junior, the designer's son.

The clutch, a beautifully smooth Hele-Shaw multi-plate, hisses as it engages and the heavy flywheel gives the car a lumbering gait but then, and it is a shock, the engine shows it is longing to 'rev'.

There were penalties for involuntary stops, as in most road trials, but there was also a speed test in which marks were awarded according to a figure of merit based upon a hypothetical relationship between car-speed and rated horse-power.

It was obvious, however, that the big engine was in the most favourable position to win in the speed test, and hence, reliability being equal, to gain the premier award.

Further, as the width and shape of the dashboard was virtually fixed by the regulations, a body was designed with a bulbous back to give a reasonable stream-line form, and to be consistent, the Prince Henry radiator and bonnet were adopted.

So many people desired cars of this special type that in 1911 it was made a regular product of the Vauxhall works, and, during the last year or so a new style has sprung up.