Does the BMW 2005 330xi have an auxiliary jack?
Do you have a CD changer in the trunk area? If not you can hook up a DICE unit to play your music via a phone. I'm also sure you can remove the radio and do the same thing with a ipod/iphone wire adapter into the back of the radio.
Search BMW 3 Series Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
BMW 3 Series Experts