Cadillac AllanteWhen it comes to building cars cost-efficiently, it’s generally a good idea to manufacture the body somewhere in the vicinity of the final assembly line.

Next door is ideal, the freshly stamped and welded body immediately making its way to the paint shop, before being baked, undersealed and despatched to the moving conveyor that will see it built into a complete car.

It’s a manufacturing sequence that most car-makers follow, although there have been a surprising number of models whose bodyshells have been built on sites some distance from the assembly line.

Rolls-Royce used to buy in shells for its Silver Shadow and Silver Spirit from British Leyland, which manufactured them on what is now the site of the BMW Mini factory in Oxford. And today, a Roller’s bodyshell comes from Germany.

Ferrari sourced bodies from coachbuilders Scaglietti, Lamborghini from Goldencar, both of these local to their factories.

Less clever was British Leyland’s habit of transporting primered bodyshells around the Midlands during the ‘60s and ‘70s, a pretty inefficient activity when most of a raw shell is air.

Cadillac and Pininfarina

Cadillac Allante

But that was nothing to the manufacturing process that produced the Cadillac Allante. This two-door convertible, which debuted in 1986 as an alternative to the Mercedes SL and Jaguar XJS, was the progeny of America’s most upscale car-maker and Italian design house Pininfarina.

Cadillac had flirted with the Italian company before, the body of its ’59 Eldorado Brougham saloon handbuilt and assembled in Turin on chassis’ sent from the US. Once Pininfarina had finished with it, the Brougham was shipped back to America for final finishing.

This was the last hand-made, coach-built Cadillac and you certainly paid for it, the Pininfarina Brougham costing three times the price of the spectacularly flamboyant standard version made in the US.

Unsurprisingly, this US-Italian hybrid sold slowly despite its more tasteful elegance, only 200 finding homes in 1959-60. There were quality problems too, the lead-loading used to smooth its hand-beaten bodywork causing the paint to fracture.

How not to learn from history…

Cadillac Allante

Despite such mixed results, GM decided to have another crack at creating something special with Pininfarina a couple of decades later.

This time, Italy got the task not only of designing a classy two-seat roadster, but also of building and painting its body as well. The broad basis of the Allante was Cadillac’s front-wheel drive V8 Eldorado, although its bodyshell, and most of its platform, were unique to the convertible.

And the name? That was generated by a computer that produced 1700 possibilities, the chosen badge being meaningless, although its did sound a little like the sea that this Cadillac’s body had to cross.

Cadillac Allante

That body was neat, slender, crisp and excitement-free, the Allante’s potential athleticism undermined by an over-short wheelbase, a curiously high-riding stance and a powertrain that was never going to threaten a sprinting SL or an XJS.

There may have been 4.1 litres of V8 beneath its long bonnet, but this engine was good for no more than 170bhp and a 0-60mph time of 9.8 seconds, languidly delivered via four-speed automatic.

All of which meant that the most dramatic aspect of the Allante was not the car itself but its crazy method of construction.

Building cars with Boeing

Cadillac Allante

Once Pininfarina had finished the bodies, which were painted, fully trimmed and equipped with their folding roofs, they were transported from Turin to America by jumbo jet.

GM called it the ‘Allante Airbridge’, a trio of Boeing 747s specially modified to carry the part-finished Caddys across the pond. Detroit installed the sub-frames, suspension, drivetrain, fuel tanks and wheels to complete the car.

Cadillac Allante

Although it was not quite complete when Cadillac launched it in autumn 1986, Pininfarina having realised that the soft-top was prone to leaks and squeaks. They wanted to delay the launch and fix the problems, but GM insisted on sticking to its timetable.

And Mother Earth stuck to her familiar weather patterns, unhelpfully showering the Allantes bought by eager owners. Who soon found that some of that rain wasn’t returning to earth, but pooling in the footwells of their prized new convertibles.

Stemming the leaks cost Cadillac tens of thousands of dollars, besides staining the Allante’s reputation. And its carpets.

Leaks were not the last of the Allante’s functional troubles. Bosch discovered problems with its ABS anti-lock brake system, and the Bose sound system made strange cracking noises that could have been mistaken for failing trim.

Cadillac didn’t give up

Cadillac Allante

By the early ‘90s, the Allante’s reputation was glittering like an old tyre. But Cadillac didn’t give up on it, despite slow sales.

The pushrod 4.1 motor was tuned to produce 204bhp before being replaced in 1992 by GM’s excellent new 4.5 litre 32-valve quad cam Northstar V8, which delivered a far more convincing 285bhp.

Despite its front-drive chassis, the Allante drove well, too, blending refinement with a decent show of twisting road agility.

And it had plenty of the toys that Cadillac owners expect, including sumptuous power leather seats, digital LCD instruments, traction control – necessary, with front-drive and 285bhp – and later in life, electronically controlled suspension too.

‘Quite decent’, eventually

Cadillac Allante

By the end of its career, the Allante had become quite a decent grand touring convertible. Trouble was, the 1989 Mercedes SL, a tour de force of engineering and quality, had the one thing that the Allante was missing, in the shape of a one-shot power roof. Which didn’t leak.

Cadillac ran hard to fix and improve the Allante in the first few years of its life, but it never ran hard enough to keep up with the SL and XJS despite some substantial improvements.

Like most cars that gain an unsavoury early reputation, it never fully recovered. Still, the ’93 model year Allante was the best yet, featuring revised rear suspension with electronic dampers, upgraded brakes and myriad detail improvements.

It was also the best sales year for the car, the 4670 sold far higher than had been achieved in earlier years. But Cadillac nevertheless announced the Allante’s demise in the same year, the model still falling short of its 6000 annual sales target.

Profligate, yet loss-making

Cadillac Allante

It’s hard to imagine GM making much money on this car when it sold an average of around 3000 copies a year, was produced by such tortuously profligate methods, shared relatively little with other Cadillacs and almost nothing with Oldsmobiles and Buicks.

The total Allante production tally was 21,430. Today you can find them on sale in America from around $8000, while the best examples, often with mileages well below 40,000, cost under $20,000 – a third of the $60,000 or so that this Cadillac cost at the end of its career.

The Allante was not Cadillac’s last two-seater, the company taking another shot at the SL with the XLR. This time without the help of Pininfarina and a small fleet of jumbo jets.