Significant changes accompany the Ion into 2005. A revised front fascia on sedans, as well as various other exterior trim and wheel upgrades, spruce up the Ion's outward appearance. Inside, new front and rear seats (on level 2 and 3 models) provide substantial comfort improvements, and a new steering wheel replaces last year's go-kartlike unit. Interior trim and materials have also been refined. Substantial improvements to noise, vibration and harshness (NVH) have been made possible through the use of Quiet Steel for the plenum and dash, an acoustic engine cover, and other powertrain and insulation enhancements. The electric power steering has been recalibrated, and various suspension revisions improve ride and handling. A four-speed automatic transmission replaces last year's five-speed unit and the coupe's CVT unit.