A few years ago the very existence of parent company General Motors was hanging in the balance but the Cadillac brand has made a spectacular comeback with an edgy design vocabulary in the CTS line and a seriously powerful headline-grabbing variant in the CTS-V coupe. The house style is sufficiently distinctive and the handling sufficiently sorted (we'll ignore the soon-to-be-killed-off Escalade) that the CTS is attracting buyers in Europe, something notoriously difficult for US car brands. Cadillac is feeling confident and that confidence was evident at Monterey last week where it unveiled a concept convertible that showcases a design direction for the future and its desire to move further upmarket, which of course, is exactly where Cadillac should be.

The Ciel (french for sky) is an long elegant boat of a car with strong design hints of previous Cadillac glories. Mercedes Benz has shown how successful you can get by incorporating body cues from the past into modern vehicles in an almost comic "retro-fabulous" style, and GM has clearly got the message. Modern metal-bending allows for shapes that were impossible in that time and you can see how the massive front and rear light clusters of bygone Cadillacs have mutated into sharp blades whilst still retaining a flavor of their iconic forebears. That hood-hump has been a Cadillac trademark since the early 70s.

While the exterior is a beautifully proportioned cruiser suitable for the Pacific Coast Highway - even the 22-inch rims look correct - GM has really gone to town on the interior. Automated suicide doors reminiscent of Lincoln convertibles past provide access to individually adjustable armchairs. The complex but tasteful hand-made interior sculpture of Olive wood, nickel-plated metal and burgundy leather is beautifully executed and though this a concept vehicle there is actually very little that couldn't make it into production - the pull-out wool blankets and the aromatherapy controls probably.

Motivation for the 203-inch (5.175 m) long car is provided by a twin-turbo V6 producing 425 hp (317 kW) assisted, of course, by an electric unit capable of wafting the vehicle silently at low speeds.

This would be a very expensive vehicle to produce. The Converj/ELA that we covered a few days ago is the future direction of Cadillac mainstream cars but it might be that GM sees a time when a handmade and unashamedly luxurious Cadillac might make a great deal of sense for the brand. If this is the quality of design and execution that they are capable of then bring it on we say.