I have an '07 A4 with the factory head unit (maybe a Symphony 2? looks like this).

Right now, the only controls that work on my steering wheel are the tuning and volume up/down wheels. The mode and other button don't do anything.

I'm looking at having an Denison Five installed, and I was wondering if it would cause my other buttons to start working.

I'd also be interested to hear others thoughts on the Denison Five.
Does it work well? What doesn't work so well? Is it easy to navigate through an iPod library? How does it work with the iPhone? Etc.

Thanks for any info!