"It's Freezing Outside, Let's Put the Car's Convertible Top Down!"

My hometown of Royal Oak, MI, once was dull. An outsider had said it skewed towards beat-up pickups and hardware stores.

Main Street had bars that smelled funny and a gun shop with creaky wooden floorboards; a place so old, you might have expected a close-out sale on muskets.

Then the in-crowd moved in, converting Royal Oak into what the state of Michigan’s economic development people officially call – no joke – a “cool city.” (Photo: Wind tunnel test shows how AIRCAP works on Mercedes-Benz E-Class Cabriolet)

We now have lots of nice restaurants, loft living quarters, upscale bars and entertainment venues. And, of course, a lot of cool people. Many of them drive around in cool vehicles.

I remember one car that literally was cool. Here’s why: No matter how cold it was outside – and Michigan winters can get Arctic-like – a guy in a white Saleen Ford Mustang convertible would tool around town with the top down.

During the deep-freeze season, he’d make the open-air motoring scene bundled up in a heavy coat, scarf and wool hat. He looked like a human Popsicle.

I’d chuckle at seeing that oddity as I looked out the window, sipped my latte and enjoyed the cozy fire in the fireplace at the trendy Caribou coffeehouse. (If you can’t beat ’em, join ’em.)

But owners of the ’11 Mercedes-Benz E-Class Cabriolet, who opt to drive around with the top down in the winter, may get the last laugh.

That’s because the 4-seater convertible is ingeniously designed to block out the cold, even when the top is down and the temperature below freezing. Credit for that goes to a new Mercedes system called AIRCAP. It creates a pressurized pocket of air that keeps the Cabriolet interior warm in the winter and cool in the summer.

It works like this: A wind deflector above the windshield directs outside airflow over the heads of the occupants. Meanwhile a mesh screen in the deflector slightly increases air pressure inside the car to keep the cold air out.

Working in tandem with that front-end stuff, a deflector screen behind the rear seats prevents backflow into the car.

So, if you activate AIRCAP and raise the car windows, you enjoy a comfortable hemmed-in cabin temperature that is in marked contrast to uncomfortable outside temperatures lurking above.

If you really want to stay toasty with the top down in frigid weather, the Mercedes convertible comes with an option called AIRSCARF. It consists of air vents integrated into the head-rest vicinity of the front seats.

The vents blow warm air on an occupant’s neck, a part of the body that is sensitive to temperature because a major artery is located there. Blood passing through the carotid artery is warmed and distributed to the rest of the body. Those Mercedes engineers think of just about everything. It took them a couple of decades to perfect this amazing climate-control system.

I tested AIRCAP and AIRSCARF on a chilly Smokey Mountain morn while driving in Tennessee and North Carolina. It worked great.

My auto journalist driving partner, Al Vinikour, and I may have looked like idiots deserving of mountain-folk guffaws as we drove with the top down in nippy weather. The locals had no way of knowing how comfty we kept in our warm air bubble.

To Al’s chagrin, I did an impromptu test of another new feature in the E-Class Cabriolet. You can raise and lower the top, even when the car is in motion. That will work at up to 25 mph.

So as we pulled into Asheville, NC – a once-sleepy town that, like Royal Oak, has become hip – I pushed the raise-top button as Al drove. Oops.

I guess I should have warned him first, because it shocked him to be driving while the top suddenly started closing in on us. OK, he didn't expect it. But from Al’s reaction, you would have thought an eagle swooped down and planted its talons in his head.

After he fussed, cussed and missed a turn due to the roof incident, we got our bearings and arrived for lunch at Cucina 24, a trendy restaurant. It reminded me a lot of home.