The standard seats have firmer cushions and increased lumbar support than previous models. We didn't find the SS seats particularly comfortable or supportive, however, with too much lumbar support and not enough side bolstering to retain the upper body in corners. Optional leather-covered seating has a new style of seams around the perimeter and French seams on the center sections.

A twin-brow instrument panel wraps around into the doors. Impala LS, LT and LTZ models have wood trim, with brushed silver trim optional. The SS comes standard with unique metallic trim panels, with wood as an option. We found the instrument panel pleasing to the eye, colorful, entertaining and easy to use, with a nice all-of-a-piece unity and style to it. Interior materials are at least one grade better than the usual Chevrolet stuff.

The dual-zone climate control system that comes on all but the base LS model is a snap to use, with large, round control knobs and good markings. It can support up to a 12-degree temperature difference side to side. The optional remote engine start system comes with a 200-foot operating range and automatic climate pre-conditioning to warm or cool the interior. The driver information center offers more than 50 different alerts, depending on the vehicle's equipment. The glovebox is large enough to actually hold stuff.

A new family of audio systems features radios compatible with Generation 7.0 OnStar. The base audio system includes AM/FM/CD and six speakers. An optional MP3/CD-radio is configured for XM Satellite Radio, with a two-line, 32-character display and the capability to select freely between AM, FM and XM. We really liked this system because we could set up all of our favorite stations in one row, for example, allowing us to quickly switch between AM news, XM news, FM music stations, and CDs. Setting these presets is as easy as holding the button down. A big round knob in the center allows quick volume adjustments. Presets for the equalizer let you quickly switch settings from rock to country & western to talk radio. Too many radios nowadays are too complex or have tiny buttons difficult to operate underway. More of them should be like GM's radios. It's sophisticated yet easy to operate. The optional ICDX radio adds an in-dash six-CD changer. Impala also offers a premium Bose audio system. All radios include a standard auxiliary input jack for external devices such as an iPod or remote cassette player.

The back seat is roomy and comfortable for two adults or three kids, but not three adults. The forward-flipping rear seat cushions reveal a storage tub underneath that can contain spills or transport a variety of items. The tub also serves as a covered storage area beneath the seat with cushions down; and exposes convenient grocery bag hooks when the cushions are flipped forward. A generous pass-through from the trunk can be created by flipping the seat bottoms forward and the seat backs flat.

The trunk is larger than that of most mid-size cars, at 18.6 cubic feet, and a huge trunk opening makes loading easier.