I was in Dresden last week, doing some research about a Phaeton that I plan to order through my dealer in Canada. I took some pictures of a Phaeton that has the Active Cruise Control (adaptive distance control) installed. This is available on the MY 2005 Phaetons in Canada, but it is listed as a 'delayed introduction' option - not sure what this means, perhaps it won't be available right away.
I did not see any 2005 North American Phaetons with this option installed, but when I did the tour of the assembly facility, I saw a 2006 North American Phaeton that did have this feature installed. The photos below are of a 2005 European vehicle - one of the fleet kept at the Dresden factory to show buyers the different vehicle colours, interiors, etc. This option is listed in the 2005 German price list at € 2.380,-
The radar transmitter/reciever is located on the passenger side of the front of the car, just below and outboard of the licence plate. You can see the slightly different front foglight bezel (the black area is radar-transparent) in the photo below. There are photos of the actual component that is behind the bezel towards the bottom of this thread.
Front Bumper, showing transmitter - receiver for ACC
The control is on the left side of the steering wheel. The small thumbwheel on the left allows you to adjust the time interval (in seconds) between your car and the car ahead of you. It regulates time, not distance, so it adjusts the distance according to the speed of the two vehicles. The buttons marked GRA+ and GRA- mean "Gradation" - pressing either button increments the speed up or down by 10 km/h (6.3 MPH).
Steering Wheel, with controls for ACC
I do not know if the North American implementation (functionality) of this will be the same as the European implementation.