No experience but the info tells you that it connects via the CD player inputs
so if you fit the iPOD unit then you cannot use the CD player (6 pack unit on
later E65 cars that is)

You can get a belkin transmitter unit that will allow your iPOD to be connected
via any FM radio receiver - such as the one in your car and with a bit of
ingenuity you could hide the power connectors too.  In this case iPOD, CD unit
and Radio all at once - all this and we get paid too..................

I don't know about the 335i, but on mine (which has TV) you could plug it in
as the external device (at the rear of the transmission tunnel) and just
listen to the sound.

In 6 months I'll order mine with the USD interface which the dealer
says is intelligent in that you can control the ipod from the car.  

Cost is high because of extra features...so I was told.
--
John Perry

http://www.redoak.co.uk
http://www.maytrees.co.uk

I have the iPod interface on my E46.  The interface was installed by the
dealer in January of 2005.

I like it.  I like it a lot.   Sound quality is excellent.   I've played
some high-bitrate uncompressed music, and I was quite surprised at the
quality of the sound the H/K sound system could provide.

The iPod interface uses the CD-changer inputs and controls.  So you get
control of five playlists on your iPod.  You name those playlists BMW1
through BMW5 (anything after the first four characters is ignored, and can
be used for further identification.  I have a playlist "BMW2 - Pink
Floyd").  The sixth "CD" in the "changer" is "all the songs on the iPod".

The radio does not display the song info on the radio display (I think the
radio in the current 3-series does).

The ability to change songs and volume from the steering wheel is nice
(though the steering wheel controls on my E46 have all but died).  

The interface plug is in the glove box, so the iPod stays out of sight.