New York (CNN Business) The new McLaren Elva supercar costs $1.7 million, not including options like a sound system or exposed carbon fiber body panels. One option you won't be able to get: A roof.

The Elva isn't a convertible. It's an open-topped roadster, meaning it has, literally, zero roof of any kind.

You can pay a little extra to get a windshield if you want. (It will be legally required to get one in some US states, McLaren said.)

To help keep the wind out of your face, the Elva's Active Air Management System deploys when the car is driven at faster than suburban street speeds, roughly 25 miles per hour. The system directs air around the cabin to create what it calls a "bubble of calm" for those inside. Air is channeled through the car's nose — or front end — and sent out in a high-velocity sheet, just ahead of the cockpit. This air acts like a windshield, forcing oncoming air around the cockpit. A small carbon fiber wind deflector also rises up at the front of the car, further directing the air around the cabin.

The McLaren Elva is designed to provide a pure roadster experience. There's no stereo as standard equipement and no roof available at all.

In the event the car flips over in a crash, occupants will be protected by an automatic rollover protection system. McLaren did not describe it but, in other cars, rollover protection systems involve strong metal rollbars that deploy from behind the passenger compartment the moment sensors detect the car is about to tip over.

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