I know I've been hammering this for a few days and don't want to come off as a know-it-all, but after a good week researching this on Becker USA, the Porsche and Mercedes groups, the factory wiring diagrams for the 6806, model 23 (the non-Nav factory Becker Head unit), conversation with the Becker USA tech, I concluded the only way in to the non-Nav head unit was through the phone connection.

I ordered it from Becker USA ($13) and installed it. You get either Left or Right speaker, a mono connection and the head unit is muted. The amp circuit from the input device provides the juice to the speakers, presumably through the power amp.

That means your iPod is going to be left or right channel only (or you can bridge them before you go in to the head unit and have mono in one channel), no power amp signal going to the power amp (if you have one), and sound coming out of only one speaker (left OR right).

It's a slightly better than nothing approach, kinda like using your iPod as an AM Radio. The constraining feature is in the head unit. When the phone mute signal is received, the head unit lets the sound coming in through the input to to whichever speaker (Left OR Right front ONLY) - you chose in the menu - not both.

Here's the unfortunate facts from the factory manual for the non-Nav head unit.



The Porsche, VW and Mercedes guys pounded their heads against the walls on this and the best they could conclude was that flashing the head unit to change this feature might work, but there was no one who actually did it.

If someone wants to find a Porsche/VW/Mercedes dealer and is willing to risk bricking a head unit or three to figure it out, there might be a way but I think it's a long shot.

Somewhere on one of these threads I found somebody said they got quoted $200 to flash the head unit with no guarantee it would come out alive or providing the correct capability.

After a week of reading circuit diagrams, some deep Becker unit specs, a discussion with the Becker USA tech, about 50 well informed forum messages, and looking at dozens of CD-emulator solutions (for the nav-unit) I concluded it was a long shot to make the non-Nav unit take aux inputs, and even assuming success with flashing the head unit, still some other costs.

The easiest and most effective path to this is simply to swap the head unit with something that takes your iPod as another input device. If you buy a moderate to expensive replacement head unit ($200-$1000) you will get at least as good sound and features (at the low end) and superior sound and features (at the high end).

If you really just like the admittedly nice look of the factory head unit, well, you are stuck with the fm transmitter/modulator routes and mediocre sound.

OR

you can go to one of those companies that take factory units and basically convert an aftermarket unit so that the faceplate looks like the factory unit but the guts are upgraded to the aftermarket unit. (Click for an example) This is very big in high-end vintage car restorations where the owner wants the car original for shows but wants quality tunes for real life. This is a cost-no-object exercise but for those who already have everything else....

I'm a dreamer - I saved my factory unit for the day when I either have everything else in the world I want and a conversion is the only thing left, or I sell the Crossfire....

I am open to being wrong but the wiring diagrams, the factory owners manual, and the tech don't lie. Oh yeah, I tried it too just to make sure...