Any idea what they installed ? I am looking to do the same to my 2007.
I had an iPod adapter installed in my 06 GS300 yesterday by a local Lexus dealer. It is a SoundLinQ2, model SL2i by Vais Technology (www.vaistech.com). The price quoted in this thread sounds about right for the retail price of this gadget, which Lexus charged me about $500 to buy and install. I'm guessing they didn't really pay $375 for it. If you know what you're doing, it looks to me like you could do this yourself (I couldn't, though). The website has all the instruction manuals posted as pdfs.
The thing works pretty well with a couple of drawbacks. Running in "CD-emulation" mode the iPod playlists show up as if they were CDs on the screen (each playlist is a separate "CD" with room for 99 total playlists). It will show the name of the playlist and the name of the track on the screen when it's playing. It will NOT however access the podcast menu on the iPod, which means if you download a lot of podcasts (like I do), you have to use "simple mode." This means control reverts to the iPod itself and you don't get any information on the screen. Not so bad, but not worth $500, either.
The other issue I'm having is that the audio quality is a little disappointing. I'm still working on it, and it may be that comparing the sound of MP3s on the iPod to the original CD running through the same speakers isn't quite fair. Nonetheless, I think the sound is less than ideal.
If anyone else has installed this gadget and has insight into the sound quality issue, I'd appreciate hearing about it.
Oh, and they have a new model specifically for the video iPod that will show videos on the console screen. Looks cool.
Thanks.