holder. The car was thought as the pinnacle of the RX-7 series (until the introduction of the FD). The Infini IV came with other special items such as black bucket seats, 16-inch BBS wheels, Knee pads, and all the other items mentioned before. There are differing years for the Infini, which denoted the series. Series I was introduced in 1987, Series II was introduced in 1988, Series III was introduced in 1990, and Series IV was introduced in 1991. Series I and II came in White or Black exterior colours, Series III came in Forest Green only, and Series IV came in Forest Green or Noble Green exterior colours. There are only minor differences between the Series models, the biggest change which was from the Series II being an S4 and the Series III and IV being an S5. The Turbo II model uses a turbocharger with a twin scroll design. The smaller primary chamber is engineered to cancel the turbo lag at low engine speeds. At higher revolutions, the secondary chamber is opened, pumping out 33 percent more power than the naturally aspirated counterpart. The Turbo II also has an air-to-air intercooler which has a dedicated intake on the hood. The intake is slightly offset toward the left side of the hood. In the Japanese market, only the turbocharged engine was available; the naturally-aspirated version was only available for select export markets. This can be attributed to insurance companies in many Western nations penalising turbocharged cars (thus restricting potential sales). The Japanese market car produces in the original version; this engine was upgraded to in April 1989 as part of the Series 5 facelift. The limited edition, two-seater Infini model received a version beginning in June 1990, thanks to an upgraded exhaust system and high-octane fuel. Australian Motors Mazda introduced a limited run of 250 'Sports' model Series 4 RX-7s; each with no power steering, power windows or rear wiper as an attempt to reduce the weight of the car. Convertible Mazda introduced a convertible version of the RX-7, the FC3C, in 1988 with a naturally aspirated engine—introduced to the US market with ads featuring actor James Garner, at the time featured in many Mazda television advertisements. Only about 22,000 convertibles were built making them quite rare. The convertible featured a removable rigid section over the passengers and a folding fabric rear section with heatable rear glass window. Power