Mmmmm, Airscarf. I left Santa Barbara, Calif., southbound for San Diego at 9 a.m. It was 60 degrees, and the sky was clear blue.

I powered back the hardtop of the Mercedes-Benz SLK, engaged the navigation system, put the seat heaters on high and switched on this car's unique Airscarf, which blows warm air from a vent at the top of the seatbacks. I smiled as the heat cascaded across my neck and shoulders.

It was a good day for a convertible, and with a retractable steel-and-glass roof, there are no bad days for the SLK.

This is the third generation of SLK, redesigned for 2012 with new direct-injection V-6, turbocharged four-cylinder engines and a new seven-speed automatic transmission. Its silver-arrow sleekness looks more graceful than past designs, but it surely has grown since the first fun and jaunty model in 1997. It is a serious, elegant car now, with a price to match.

You'll know this generation's SLK by its long hood and wide and serious face, which picks up the family trait from the CLS coupe-sedan and SLS AMG coupe.

Pricing for the SLK250, with its 201-hp, 1.8-liter engine, starts at $43,375, with a six-speed manual transmission. Fuel economy ratings are 23 city and 31 highway.

And the 415-hp, 5.5-liter V-8 SLK55 AMG goes on sale this month, with a starting price of $68,375.

The SLK350, today's test car, starts at $55,675 and has the 302-hp, 3.5-liter V-6 and seven-speed automatic.

The as-tested price was $68,965, and the car came with some interesting options, including Bengal Red leather upgrade ($630), Iridium Silver metallic paint ($720) and the Magic Sky Control panorama roof ($2,500). The glass roof, similar to auto-dimming mirrors, can be switched from clear to dark. Nighttime winter skies and urban scapes bring some theatre to the drive.

New standard equipment includes rain-sensing wipers, power-folding and auto-dimming mirrors, power memory seats with lumbar support, HD Radio, integrated garage door opener and a rearview mirror with integrated compass.

Unlike most retractable hardtops, the arrow shape of the SLK looks good with the top up or down. And the chassis is tight and solid, top up or down. Airflow is somewhat blustery at interstate speeds, but it's nothing the optional Harman Kardon Logic7 audio system can't penetrate with clarity. There is a standard fabric air deflector that mounts to the roll bars, but the test car also had the optional Airguide windstop deflectors ($350), which are adjustable Plexiglas panels that mount to the backs of the roll bars. The top cycles in about 20 seconds, but only when stationary.

Interior features are rich in textures, quality appearance and assembly. However, my DroidX phone would not connect. The large front seat area doesn't feel cramped with the roof up. Sightlines are good, particularly for glances over the shoulder, but a rearview camera's guidance lines would be a help when parking on the street.

Ride quality is sports-car firm, and the suspension in sport mode can give a jolt over rough pavement. The V-6 tools along easily on moderate throttle and makes a good, meaty sound when making a hot, double downshift for passing power. Mercedes claims 0-60 mph in 5.4 seconds. With an 18.5-gallon fuel tank, the SLK has a long cruising range.

I liked the rich, fluid motion of the hydraulic steering and the small, 34.5-foot turning circle. However, the long doors complicate entry and exit in tight parking slots. And the seat belt tab frequently would get stuck in the upper seatback guide, which required reaching around to guide it through the narrow opening. (This would never happen in a Honda.) And for the money, a heated steering wheel should be available.

The SLK is an expensive convertible because it is two cars in one — and it fills both roles without compromise.