along with a "next-generation" supplemental restraint system that added a passenger-side air bag. The SS package was replaced by the "Xtreme" package. In 2001, a crew cab option was added and was only available with four-wheel drive and an automatic transmission. For the 2004 model year, the regular and extended cab models were discontinued; only the crew cab model was retained. Base two-wheel drive models came with 15 x 6.5-inch wheels with directional vents, Xtreme and ZQ8 models came with 16 x 8-inch wheels while four-wheel drive models (including the ZR2) used 15 x 7-inch wheels. The wheels used on the first generation were discontinued. Electric versions Solectria Corporation offered the E-10, which was an electric vehicle conversion of the S-10 starting in 1993. U.S. Electricar also offered S-10 conversions starting in 1994. In 1997, General Motors introduced the Chevrolet S-10 EV, a battery-electric version of the S-10 pickup. The S-10 EV used the same front-wheel drive powertrain as the GM EV1. 1998 Restyling For 1998, the Chevrolet S-10, GMC Sonoma, and Isuzu Hombre received a mid-cycle refresh. On the exterior, the front fascia was redesigned, and new wheel designs were added. The interior received a full redesign, with "TheftLock" anti-theft functionality for most radios, improved audio systems (including newly designed radios), new interior front door panels, an optional combination cassette and CD player radio, redesigned keyless entry remotes, a new steering wheel, dual airbags, a new instrument cluster with digital odometer and gear shift indicator for automatic transmission-equipped models, and new seat fabrics. Crew Cab (2001-2004) In 2001, a four-door Crew Cab configuration was introduced for the Chevrolet S-10 and GMC Sonoma. Available exclusively in LS or SLS trims, the Crew Cab included many features that were optional on other S-10 models, such as full power accessories (windows, door locks, exterior side mirrors, and keyless entry), dual front bucket seats, fifteen-inch (15"), five-spoke aluminum-alloy wheels, an A/M-F/M stereo radio with TheftLock capabilities, a single-disc CD player, and Automatic Tone Control (ATC), a six-speaker audio system, a tachometer for the instrument cluster, and air conditioning. Leather-trimmed seating surfaces were also introduced for the Crew Cab for the first time for the 2001 model year. ZR-5 Sport Package Available exclusively on the Chevrolet S-10 and GMC Sonoma LS and SLS Crew Cab models, the ZR-5 Sport Package was a sport appearance package that added black front and rear bumpers, fifteen-inch (15")