Eight automotive inventions that never quite caught on

Have you ever wondered how the designers of modern cars manage to cram so many useful features into a small space? Or just how weird our cars would be if every idea dreamed up by well-meaning boffins found its way into every automotive design.

Some ideas date back to the very dawn of motorised transport. Others are recent inventions that have flourished briefly and just as quickly fallen from favour. Remember any of these? Or even better, do you own a car that includes one or more of these fabulous failed features?

Every few years, accompanied by a splash somewhere off in the distance and sound of a small, marinised engine, comes news that someone has devised a new amphibious vehicle. Military forces have explored the concept for decades but the idea of driving a normal-looking car into a river instead of parking it and catching the ferry seems hard to justify. Several designs since the 1960s have taken the plunge, with the most viable being the Amphicar. These were built from 1961-68 and around 3000 were made. Mechanical parts came from the British Triumph Herald but with bodies made predominantly from steel, longevity wasn't a major feature. Several survive in collections and a small fleet (or flotilla) still provides tours of waterways adjacent to Disney Springs in the US state of Florida. Occasionally we have Amphicars listed here on carsales!

Here we are not talking Chitty Chitty Bang Bang or even Ron Weasley's magical Ford Anglia. These are actual vehicles with names like Aerocar, XPlorair and the Terrafugia Transition. Even Henry Ford got involved way back in 1926 when he built a 'Flying Flivver' based on his famous Model T. It quite literally didn't get off the ground and killed the test pilot on the one occasion that Ford tried to make it fly. The Aerocar from 1949 was a pretty little thing but could only carry one person and production stopped after six had been made. The Terrafugia looks the most viable of recent designs with an air-speed of 172km/h and road speed of 112km/h. It uses a Rotax piston engine and seats two people but with a projected price of US$300,000-400,000 we have our doubts that the Terrafugia will - wait for it - get off the ground any time soon.

While being able to 'go while on the go' has its benefits, the implications of things going wrong while seated on your automotive throne are too horrible to contemplate. That did not deter Cadillac, which in 1947 invented an in-car dunny so drivers involved in a 10,000 mile endurance run weren't continually stopping when nature called. That should have been the end of a silly concept, but in 2012 a Chinese company installed 'piddle panels' into car seats with a storage tank in the boot. That idea mercifully failed as well but five years later Toyota announced that its Innova people mover could be equipped with a full-sized camping toilet mounted behind a screen in the luggage area. Honey, I stank the kids.

Revenge must have been sweet for the designer of Holden's LX Torana 'Hatch Hutch'. Very likely a child who had been forced to sleep in the annex during family caravanning holidays, this individual was destined to devise a zip-up vinyl cocoon to enclose the Torana's luggage platform; where only a contortionist or masochist would attempt to sleep. The Hutch when new added $65 to the cost of a three-door Torana but hardly anyone was mug enough to take up the offer. Today they are hot items and essential when restoring a Hatchback Torana all the way to concours d-elegance glory. Find a Hutch still in the original wrapper and the price will very likely exceed $1000.

Back in the days when people travelling by 'horseless carriage' still had a hankering to remain horse-drawn, a bright character by the name of Uriah Smith moulded a life-size horse's head and shoulders that could be attached to the front of early vehicles. In addition to soothing the motor car's occupants, Smith's intention was also to make genuine horses believe that the rapidly-approaching Nodding Neddy with its attendant cloud of acrid smoke was one of their own. Just how many were sold we cannot say, however it was one of prolific inventor Smith's last efforts as he died just a couple of years after presenting his attempt at equine subterfuge to the world.

Promoted as a safety device that encouraged the driver to watch the road rather than constantly checking gauges, the HUD has proved to be divisive and expensive. The system was first adopted for automotive use in the late 1980s and in the beginning it was heavily promoted by General Motors in the USA and by Toyota and Nissan in Japan. HUD in modified form it remains available in some high-end European models and as an option for the visors of motorcycle helmets. The major impediment to more widespread use is the need for a specially-made windscreen onto which information can be projected. If a crack or chip is too serious to be repaired, a replacement 'screen will cost around five times the price of a standard windscreen.

Another device that enjoyed a surge in popularity and remains in use today is four-wheel steering. The vast majority of past and current users are Japanese manufacturers with Nissan leading the way. Its HICAS system appeared in 1985 and within five years there was hardly a top-shelf Japanese model that wouldn't swivel its hips when maneuvering in tight spaces. 4WS systems were designed to switch off when the car hit 30km/h but there was always a nagging doubt that they might deploy at precisely the wrong moment. Owners of high-performance 4WS models like the Nissan GTR 'Godzilla' and Mitsubishi's rally-hero Galant VR4 hated the extra weight and mechanical complexity so the system was invariably the first thing flung when preparing cars for competition. Today you can find it on the Renault Megane RS.

This invention remains in vogue with several major car-makers but generally is loathed by people who struggle to live with the limitations of run-flat rubber. Once manufacturers decided that a conventional spare wheel added weight and cost, a tyre that could be sealed using a can of goo seemed a good idea. That wouldn't work when the wall or tread had a great chunk out of it, so then came the idea of the 'run-flat' tyre. These appeared commercially in 1983, marketed by Dunlop as the 'Denovo' and were followed by designs from Pirelli and Bridgestone. Adoption levels by European and British manufacturers peaked during the late 1980s but are now in decline as buyers resist the higher cost, harsh ride and faster wear rates of the run-flat.

Related: Awesome road technology you might not know exists

Related: We take a look back at who killed the car phone

Related: Five tech features all cars should have