Technology on Top- Appreciating the Luxury Learning Curve

As the International Auto Show opens in Detroit this week, the growing number of "retractable hardtop" convertibles on display is a reminder of how, every once in a while, technology sort of catches up with itself in an interesting way. Something anticipated years earlier finally comes into its own in the marketplace because advances in engineering, materials or systems design make it more reliable and affordable.

Hardtop convertibles have been gaining in popularity and dropping in price in recent years as the technique and technology of folding a solid (usually steel) roof into a package small enough to fit in a car's trunk becomes more refined.

Advances in lightweight materials; smaller, more powerful and efficient electric motors and better sealing materials, have combined with clever design and engineering to make retractable hardtops much more feasible and trouble free than they were when the first efforts were made to have the best of both worlds - open air driving and sedan like quietness and security.

The Mercedes-Benz "Vario-roof," introduced on its SLK roadsters in 1996, is the epitome of sophisticated drop tops and has been perfected over the past decade to new levels of quiet, seamless operation. In its most sophisticated form, on the SL series convertible, it goes up or down in 16 silent seconds without the driver having to do anything but touch the control switch. The top on the Lexus SC430 convertible is almost as impressive - not quite as fast but possibly even more quiet.

But now there is an interesting group of more affordable hardtop convertibles broadening the market. The 2007 MX-5 Miata, from Mazda, is an excellent example, offering a retracting hardtop in the $25,000 price range. Its ingeniously engineered top, made of lightweight polycarbonate, folds in three sections and takes up no more space than the Miata's standard fabric top. The Miata is still the best selling two-seater in the world, and the new hardtop, giving it a quieter and more secure feeling in rainstorms and winter weather, promises to give it even more cred among two-seater enthusiasts.

Another impressive hardtop, though at a heftier price ($28,000 to $36,000) is the Volkswagen Eos. I recently drove one and was impressed with the speed and quietness of its top mechanism. The clever manner in which the roof stores behind and around the rear seat allows for a roof line with fewer "cuts" for folding hinges. The top also transforms into a sunroof when the driver doesn't want to go completely topless. Volkswagen calls this unique design a CSC (coupe-sunroof-convertible).

Volvo's new C70 convertible, priced around $40,000, incorporates a hardtop that gives the car a sleek and impressive look up or down. Watching the intricate minuet of the three roof sections when raising or lowering the top is a show-stopping experience. This three-section roof allows it to fold up smaller in the trunk but it means that the car's roof line has more hinge cuts, and these seams, however discrete, are more noticeable on C70s painted lighter colors.

In the $30,000 price range, the new Pontiac G6 coupe offers a clean-lined, fairly roomy four-seat retractable whose roof mechanism is engineered and built by Karmann, the German firm with more experience in convertible tops, both soft and hard, than any other manufacturer. However, there has been some feedback regarding trunk leaks and irregular roof motor operation by a few G6 owners.

The open air freedom of a convertible combined with a roof offering a smoother profile, more security when parked and better protection from the elements has been an intriguing challenge for engineers and designers. Solutions to the challenge have been exotic and expensive and usually pursued at the luxury car level. Going against this trend, Mitsubishi introduced a retrac hardtop in 1995 on its 3000GT Spyder. But although these cars were well done, they were twice the price of the regular Spyder and only a little over 1600 were sold.

Before that venture, the most memorable effort in the development of rectractables was the famous Ford Fairlane 500 Skyliner introduced to the public 50 years ago. The 1957 Skyliner is recognized as the first mass produced retractable hardtop. Back in 1934, the French maker Peugeot had introduced an elegant retractable hardtop coupe, the Eclipse (great name!), but it was virtually custom-built in small numbers for only a few years. Peugeot had intended the Eclipse roof mechanism to be electrical, but problems with wiring, electrical motors and underperforming batteries led to manual operation.

A sensation when introduced, the Ford accommodated its massive, heavy top (it was, after all, a full-sized six-passenger convertible) in a huge trunk space. Did I say huge? If you are ever at an antique car show and happen to see a '57 Skyliner, get a gander at the trunk when the top is up. It's like looking into a vacant warehouse. You can hear an echo.

Such mega-trunks were common in the '50s when cars had huge overhangs, but to swallow up its top the Sunliner had a noticeably longer and higher rear end compared to Ford's regular "Sunliner" 500 soft top convertible, which was still offered. And when the top was down, the Skyliner, like most of today's rectractables, left very little space for luggage or anything else.

The Skyliner employed a complex, yet surprisingly reliable retraction system that was schematically reminiscent of the Peugeot roof. But the Ford was powered, using 7 electric motors and 610 feet (!) of wire lacing together 10 limit switches, 10 relays and 8 circuit breakers. Watching the huge roof of the Skyliner maneuver in or out of the cavernous trunk of the car was a rubber necker's delight that took about 40 seconds - an agonizingly long time in a sudden rain shower.

Ford sold more than 20,000 Skyliners in the 1957 model year, despite the fact that it was the most expensive Ford. (It cost $2942, which was $427 more than the Sunliner convertible.) Sales fell to 14,713 in 1958 and just under 13,000 in 1959, the car's last year. During those three years Ford sold 158,623 of its conventional "ragtop" Sunliner convertibles. The Skyliner was expensive and time consuming to build. Ford is said to have lost money on every one it sold. After its demise motorists would wait a long time for retractables to reappear.

Their recent proliferation is due not only to material, electronic and engineering advances, but also to the fact that the marketplace has changed a lot. There are many more buyers of luxury cars than ever before, which has allowed for the technology to be produced, used and perfected in ever greater volume. This luxury learning curve has now paid off for the broader automotive market, making a greater variety of more affordable rectractables available.

Convertible sales have been booming in the first decade of the 21st century, with such cars as the ragtop PT Cruiser, Ford Mustang and VW New Beetle giving competition to the venerable Chrysler Sebring and the highly acclaimed Toyota Solara. There are more people buying convertibles as second or third cars and the hardtops give them even greater choice. It's an old story, really - part of the magic of the market.