thing is, you have to look at the times those reviews where made. When the archos 5 first shipped back around new year, the radio transmitter worked as you have read. But more recently archos released a firmware update that disabled the transmitter unless it detected the presence of the car dock (as it provides a much better antenna then just using headphones).

for instance, that video you linked to was made and uploaded back in december 2009. We are now writing august 2010. Thats 8 months where things have changed. And this have changed, just look at this list of updates: http://update.archos.com/7/archos5/c...e_archos5.html

Sadly, archos do not mention the car dock change there.

and funny enough, checking the archosfan forum, it seems that the actual part of the car dock that do the "magic" trick is the charger. And it do not even need to be plugged into the car to work, just the archos. Makes one wonder why they have to made a transmitter snap-on, like the dvr snap-on or similar.