the rear fenders which feed the aft-mounted radiators and help cool the brakes. A horizontal hood gap also feeds air to the engine. Two small aft vents expel air that is collected by an underbody air scoop and used to cool the titanium exhaust pipes. Dual hood ducts serve to move hot air away from the exhaust manifold. The LFA's speed-sensitive rear wing incorporates a Gurney flap and deploys at speeds over . With the wing retracted the LFA's body has a drag coefficient of . The LFA body was offered with a choice of 28 standard exterior colours, along with 3 wheel colours and a matte black option. Additional special colours are available to order. The front and rear fenders, doors, roof rails, and rocker panels are made out of blast fiber reinforced sheet panels, while the tail lamps are light-emitting diode (LED) lights. Interior The LFA interior incorporates carbon fibre, leather, alcantara, and metallic surfaces. There are two bucket seats, and Lexus' Remote Touch controller interface. The interior design uses bespoke materials and colours. The instrument display is a digital thin-film transistor (TFT) speedometer with colour-changing background, size-changing numbers, and side-appearing submenus. In operation, the TFT display shows small digits in automatic mode; larger and bolder numbers in normal mode; inverted colours, moved redline, and stark numbers in sport mode, along with a programmable redline warning colour change. The tachometer display also features an electric movable metal ring with layer acrylic plastic to create a 3D effect. The LFA further features a new driver and passenger seat-belt airbag design increases similar to the S-Class ESF safety concept car. The steering wheel features a right-mounted start button and alloy paddle-shifters. To start the car, the driver must insert the key beside the steering wheel then press the start button. Two octaves of engine sound are channeled into the cabin via twin ducts which connect the firewall with the intake manifold, with the sound tuned in the manner of an Ovation guitar. A 12-speaker Mark Levinson sound system with compact lightweight components was also developed for the interior. Custom-made Tumi suitcases are designed for the LFA interior, with a two-piece set made from carbon-fibre style materials and inscribed with the VIN; a smaller "concourse" case is for track days and short trips, while a larger "coastal" case is for longer trips. Nürburgring package On 15 March 2010, Lexus detailed the