At a Apple press event here, Audi, Volkswagen, Honda and its Acura luxury division showed off their yet-to-be-released cars sporting the latestlinked to the stereo system and other volume controls on the steering wheel.
When installed by a car manufacturer or the dealer, the iPod is tethered to the stereo behind the dashboard with an access line running either to the glove compartment or a lockable center console.
currently support iPod kits, including BMW, Mercedes-Benz USA, Volvo, Scion and Ferrari.
With its additional partners, Apple estimates that more than 5 million cars will ship with iPod support in the United States in the next year.
"By 2006, 30 percent of all cars will come with an option of connecting to an iPod device," Apple CEO Steve Jobs predicted during the press event where the Rokr phone and iPod Nano were also announced.
The deal with automakers differs from iPod integration products Apple endorses withsuch as Alpine, Clarion, Pioneer and Kenwood. Custom kits from those companies range from iPod-ready units to self-install options to professionally installed products.
Honda and Acura said they would augment their iPod connector kits with text-to-speech capabilities, which representatives with the company said can be used to search for playlists and other title information.
Volkswagen, Honda and Acura said they would offer iPod support for the majority of their 2006 U.S. lineups. Audi said it would feature its iPod connectors only in its A3, A4 and TT models.
Audi and Volkswagen said they would also offer a separate iPod connector kit to dealers for outfitting its vehicles as old as 1999.
The kits can be purchased separately for as much as $175, not including dealer installation fees, each carmaker said. The kits would be recommended to only the most tech-savvy customers who don't mind spending a couple of hours underneath the dashboard.