All Cayennes get Bluetooth, iPod/USB, a capable standard AM/FM/MP3/CD audio system, cruise control, automatic climate control, and automatic stop-start with automatic-equipped models.
The optional Adaptive Cruise Control system can maintain following distances at speeds between 20 and 100 mph, and it will prime the braking system when needed and even stop. A quick press of the accelerator will reactivate the system.
Available options, some of which are standard on the top-end Cayenne Turbo, include ParkAssist with rearview camera, an electric slide/tilt moonroof, dual-screen rear-seat entertainment system, and both Bose and Burmester audio systems. The Burmester in particular is an auditory feast.
One caveat with all of these high-end available options: you can put them on your build sheet, but they'll add up quickly on the bottom line; it's easy to push the Turbo as high as $125,000-$150,000 when loaded with all of the extras, plus high-end design features like custom Porsche wheels, paint, and upholstery.