Newer technologies are making it easier to fit more into less vehicle-interior space.

For example, Ident NA Technology LLC sensors, as small as a fingertip, can be positioned throughout the vehicle and eliminate much of the wiring traditionally needed for power switches.

“Our sensors can be moved around the vehicle and used to increase volume and change stations,” Stefan Donat, chief operating officer of Ident NA Technology, says at the recent Ward's Auto Interiors show in Detroit.

“There are no cables, no wires. We developed an RFID (radio frequency identification) system. It's a reading device that gets back a signal, and you put the human body in between because it's conductive. People can transmit a little bit of energy.”

Donat says there are at least 20 different applications for the sensors, and that Ident can get rid of approximately 20%-30% of the wiring with its new technology.

TRW Automotive frees up more space in vehicle interiors by increasing electronic functions, using integrated electronic-control panels, touch-sensitive switching and steering-wheel switch integration, says Dan Mittelbrun, senior manager for TRW Automotive's body controls system division.

The number of user-interface electronics and functions in a vehicle is increasing rapidly, and integration and packaging of these features is driving additional user interface controls and displays, he says.

Integrated electronic-control panels in the center stack are eliminating switches on the dashboard and throughout the vehicle, says Tim Yerdon, who is responsible for tracking and analyzing market trends for Visteon Corp.

But less is best doesn't always prevail, at least not according to a 2007 J.D. Power and Associates customer-satisfaction survey in which large and simple rotary knobs found on less-expensive vehicles scored higher for ease of use.