Hi there and welcome to Just Answer. Thanks for asking your question.
I'm a 335i owner and have watched with interest the retrofitting of an iDrive (CCC version) to an E90 3 series. It is documented in this message board thread: http://www.e90post.com/forums/showthread.php?t=131416
It's a huge job and with dealers charging close to $90/hr, I think you are looking at at least $2500-$3000 in labor. Plus, I guarantee you that you will need a harness or a connector thet you possibly overlooked when obtaining your parts.
Anserwing your question is difficult because the only thing I would probably do is call around every dealer in a 100 mile radius and ask if they would be intereted in doing it. You may also want to talk to some of the independant shops.
Here is my suggestion, get on E90 post ( I know you have an E60) and go to this forum:http://www.e90post.com/forums/forumdisplay.php?f=44 That is the forum for your geographic area.
I would ask for dealer recommendations in there and you may get some response. You could also post in the original thread. The fellow who did the retrofit will have a whole deal of knowledge that will benefit you immensely.
If you have a follow up, I'll be here.
I wish you the best of luck - that's a very ambitious project.
I have a good friend that is the service manager at Bel Air BMW in Maryland.
Call this guy, tell him Steve Gardner with the 335i referred you. He may be able to refer you to a dealership in your area.
Joe Driscoll
(XXX) XXX-XXXX
Bel Air BMW
The dealership has multiple locations so just ask for Joe Driscoll at Bel Air. He is very knowledgeble - I had real issues with my new generation iDrive and he went to bat for me with BMW and got it working.
Let me know.
Thanks.
BMW Owner
I currently own a 335i E92 and a E46 M3