Got this from a post at the MRT forums.
http://ipodcarparts.com/clarion-cenet-r ... p-253.html
Looks like Clarion have come up with an iPod CeNet interface that allows control of the iPod. The write up for this product says "the iPod's click wheel controls are still used for song selection, play control, etc" which sounds very promising compared to the EA1251 which requires you to create fixed playlists in your iPod.
I've sent them an email asking for the Clarion model number and then I'll research it further.
Given the brief write up (it is a bit lacking in detail) do you guys reckon this would work on the McIntosh systems our local Subaru's?