Hi - I have the integrated IceLink Plus Dension unit for my Audi - but have tried the IceLink FM in my Saab.
Unfortunately the FM version didn't work well for me. The iPod integration part was acceptable (certainly not up to the quality of the IceLink Plus) - but the radio reception was somewhat compromised as a result of having the aeriel feed intercepted.
It was particularly bad in areas where there were several FM transmissions of the same channel at similar frequencies (i.e. most of the way along my route to work
). It manifested itself as a series of clicks and pulses that could be heard over the transmission. Occassionally it would completely loose the reception tuning. I tried disabling RDS - but that didn't help.
I sent back the first IceLink FM thinking that it might be a fault on the unit - but the replacement was just as bad. I can only assume that the quality of internal components were not up to scratch.
The suppliers were quick to blame the quality of installation - but I sent them a comprehensive list of all the different installation options that I had tried (e.g. different ground points, different power points, encasing the unit in an RF shield, etc). In the end they sent me a refund. I had to resort to 'hacking' the head unit in the Saab to get a direct line in - which works a treat.
I have not had experience of the Harmon Kardon Drive + Play - one would hope that it would be of better quality. I guess the solution is to get them on a try-before-you-buy basis.
Ben