I have an '04 645. The retrofit is a simple process. Search the forum; it's been covered several times, but essentially involves replacing the 6-CD changer in the glove box (you could do this yourself) with an ipod kit and then reprogramming from the dealership.
Originally Posted by FLIGHT20THREE
Does BMW offer the IPOD hub kit for 04 645's?
Nick / TopDownInFL (sans the "top down")
2012 650 Coupe - Alpine White / Black Interior / M Package / Premium Sound
2008 650i Convertible - Monaco Blue / Saddle Brown Pearl Leather / Premium Sound / Sport / Cold / Comfort Access / Lane Departure / HD Radio / Sat Radio
2004 645Ci Convertible - Reverse Sensors / Reverse Camera
/ Retro iPod
2005 545i Sedan
2003 330Ci Convertible
2001 330Ci Coupe
1998 323i Convertible
1995 318i Sedan