Marriages of convenience rarely last. The love affair between Citroen and Maserati was short, sharp but anything but sweet.

It did however produce one worthwhile offspring: the Citroen SM.

Less than 13,000 examples rolled off the production lines and those that survived have become sought-after collector’s items.

The marriage between Citroen and Maserati began with a lengthy courtship which started in the 1960s. Citroen was short on cash but full of big ideas. It wanted to build an advanced two-door coupe but was short of a decent engine and a willing partner. It's search eventually took the French company to the door of Maserati.

Naturally, the Italian firm was in an even worse state than Citroen. A cooperative venture looked like the best chance of survival. So the wedding vows were duly exchanged at the Geneva Motor Show in 1970.

Citroen got its big coupe, called the SM, and Maserati received some much-needed liquid assets.

The SM was certainly a good-looked. It's curvaceous bodywork was even more aerodynamic than the Citroen CX and the Maserati engine beneath a the bonnet gave it the go as well as the show.

Mazda handed over the keys to a 2670cc V6 (essentially a development of its lauded V8) that had been created with the SM in mind. A sophisticated design, it developed an impressive 178bhp.

Citroen's engineers adapted the sophisticated hydropneumatic suspension, already in use on the DS, to make it stiffer and more sporting. However, the SM still had a magic carpet ride by contemporary sports car standards. The system's self-levelling ability was useful, too, and made the big coupe surprisingly practical. Disc brakes all round handed the stopping and the steering was tweaked to make it more responsive.

Despite these promising changes, Citroen couldn't bring itself to fully commit to a sports car and, as a result, the SM was neither one thing nor the other.

It was launched shortly after the Geneva get together and by the end of 1971 just 6,000 had been sold - far short of overly optimistic sales predictions.

In England it was only ever available with left hand drive so sales were predictably dire but it did well in France and, more surprisingly, the US.

Worse was to come. Just as the SM was starting to find its feet the fuel crisis arrived. Almost overnight the SM became an automotive pariah. In Britain, drivers couldn't even fill the 20 gallon tank thanks to fuel rationing.

Then there was the engine. Although it sounded great and went well, the V6 suffered the usual Italian maladies. Head gaskets would blow with monotonous regularity and the primary timing chain would run slack, flailing around inside the cases and, in some case, causing the valves to hit the pistons with disastrous - and very expensive - results.

In the UK owners found themselves left with a reluctant dealer network. Only 25 garages were authorised to work on the car and, according to some of the poor mechanics, training for the SM was cut short because so few had been sold.

In 1972, an SM cost £6200, at a time when a Jaguar XJ 4.2 would have set you back a mere £3000, but the car was even more costly to Citroen which had to fork out an average of £1000 per car on warranty issues.

Citroen worked hard to improved the car's sporting performance first with fuel injection, then with a larger three-litre engine and an automatic option, but buyers were having none of it.

Naturally the alliance with Maserati didn't last and in 1975, the year SM production finished, Citroen was taken over by Peugeot.