In 1999, Pontiac delved into the minivan market with the release of the feature-rich Montana. In 1999, one or two sliding doors could be chosen for the Base model, side-impact airbags were made standard, as were 15 tires, and several new optional packages were added. An updated V6 engine, new antilock brakes, improved electrical system, updated climate control, oil-life monitoring system and updated gauge cluster marked the major changes for 2000. The biggest addition for 2001 was the optional third-row seat, which could now flip or fold. OnStar was made standard, so was remote entry, a CD player and all-powered accessories. Nominal changes were in store for 2002-2003, with subtle updates being made to trim levels and optional packages. In 2004, Versatrak all-wheel drive was made an option for all trim levels, and front/side impact airbags became standard. All-wheel-drive and regular wheel-base models were canned for 2005, with no other major changes taking place.