Dension equipment doesn't work on any of the new 2005 HU's, apparently it's something they are working on but as yet theres no fix.
Personally i don't see why people gladly pay £150 for a product you can get for £85 from halfords - Connects2 ARNIPOD003 which is exactly the same piece of equipment, and on the contrary Dension even uses some of their connections in their own over-priced package.
Takes 5 minutes to fit, and in my 53 172 it allows me to change tracks/volume from the steering mount, and obviously allows control via the iPod still. It also normalises the sound so you don't get interference.