limited production run of special North American models known as the Leathersport Models. This package was essentially an uprated GS model with added LS badges on each B-pillar, special stripes on the exterior, and LS-only gold anodized wheels (with polished outer face and wheel rim). All LS editions came equipped with special LS-only full brown leather upholstery, leather-wrapped steering wheel, leather-wrapped shift knob, removable sunroof, LS-specific four-speaker AM/FM stereo radio with power antenna (though listed as a six-speaker stereo, as the two rear dual voice coil speakers were counted as four speakers in total), remote power door side mirrors, and other standard GS equipment. Two primary options were also available; a three-speed JATCO 3N71B automatic transmission and air conditioning. Other GS options such as cassette tape deck, splash guards, padded center console arm rest and others could be added by the dealer. The LS model was only ever available in three different exterior colors: Aurora White, Brilliant Black, and Solar Gold. No official production records are known to exist or to have been released. This series of RX-7 had exposed steel bumpers and a high-mounted indentation-located rear license plate, called by Werner Buhrer of Road & Track magazine a "Baroque depression." Series 2 (1981-1983) The Series 2, referred to as the FB (produced from 1981 to 1983), had integrated plastic-covered bumpers, wide black rubber body side moldings, wraparound taillights and updated engine control components. While marginally longer overall, the new model was lighter in federalized trim. The four-speed manual option was dropped for 1981 as well, while the gas tank grew larger and the dashboard was redesigned, including a shorter gear stick mounted closer to the driver. In 1983, the speedometer returned for the RX-7. The GSL package provided optional four-wheel disc brakes, front ventilated (Australian model) and clutch-type rear limited-slip differential (LSD). This revision of the SA22 was known in North America as the "FB" after the US Department of Transportation mandated 17 digit Vehicle Identification Number changeover. For various other markets worldwide, the 1981–1985 RX-7 retained the 'SA22C' VIN prefix. In the UK, the 1978–1980 series 1 cars carried the SA code on the VIN but all later cars (1981–1983 series 2 and 1984–1985 series 3) carried the FB code and these first-generation RX-7s are known as the "FB" only in Northern America. In Japan, a very well appointed version similar to the export market GSL arrived late