BY THE SKIN OF YOUR WHEELS
In the world of BMW's outrageously designed concept vehicles, a car with a rubber shell is par for the course.

This is BMW's Gina Light Visionary Model, a concept car from the German automaker launched earlier this year. Gina stands for 'Geometry and functions In "N" Adaptations'. Silly, tongue-twisting acronyms aside, Gina is a "think out of the box" philosophy that encourages BMW designers and engineers to devise completely different solutions to the issues of the day and reinvent the wheel.

"The Gina philosophy," says Chris Bangle, head of BMW Group Design, "is about being flexible, thinking flexible, acting flexible."

And what could be more flexible than rubber? Or as adaptable. The Gina Light Visionary Model features an external shell made entirely of rubber. Or more specifically, a flexible yet expansion-resistant polyurethane-based skin. One that stretches in an almost seamless whole across the length of the car.

Interesting idea. And the end result sure looks pretty. But what exactly is wrong with good ol' fashioned steel?

Well, BMW design chief Bangle would argue that the requirements for structural rigidity, handling and personal safety are more than adequately managed with a spaceframe-type chassis. In other words, frames in modern cars are more than tough enough to handle the rigours of the road, even sans metal shell. So apart from keeping the air-conditioning in and being something for paint to stick on, metal shells, Bangle says, don't really do much.

At another level, the Gina Light Visionary Model is BMW's take on minimalist engineering - as few components and production stages as possible using technologies that require less raw materials and energy.

Yet hidden beneath all that rubber and minimalist overtones is a movable subframe operated by hydraulics. Put a changable frame into a flexible skin and you end up with a car that can, at least in theory, alter shape at the touch of a button.

The Gina's morphing ability isn't quite up there with the Transfomers. Think front grills that can open larger to aid cooling, a bonnet that splits down the middle for easy engine access, and headlights that stay concealed when not in use, yet open (like human eyelids) when lighting is needed. Not quite omnipotent autobot, but you get the idea.

BACK TO THE FUTURE

Based on the BMW 328 that won the legendary Italian cross country race of 1940, BMW's Mille Miglia Concept Coupe was unveiled in 2006. And it still looks a jawdropping stunner two years on.

retro coupe makes for a fascinating case study on how the past, present and future of automaking can be synthesised into one soulstirring modern automobile.

Drive components for this Concept Coupe are lifted from the BMW Z4 M Coupe, including the 3,246cc inline six that puts out 350 horses. It also features an entire shell made out of carbon-fibre reinforced plastic (CFRP), and painted a delicious shade of vintage silver.

In the interest of reducing weight and increasing torsional stiffness, doors are a thing of the past. Behold instead a cockpit that swings upwards to let driver and passenger in. There's not a lot that is "old" in this retro Beemer.

Don't rush to your nearest BMW dealer for a test drive just yet though. The Bavarian automaker says there are no plans to take this concept car into production.