When I was looking into the differences (mostly here on X5 World) between the 4.8is's in MY04 and those from MY05 and I found that there were “early 2004’s” and “late 2004’s” and the early ones were missing some of the newer features that many of the late 2004’s and all of the 2005’s had. It looks like it would be hard to figure out what was insatlled on any given individual vehicle without running through the full list of options. Note: It was a while ago, and I'm not 100% sure - especially in Australia and w/ respect to the 4.4i instead of the 4.8is but here's what I found anyway in case it's helpful....
[FONT='Arial','sans-serif'][/FONT]
[FONT='Arial','sans-serif']4.8is differences between early 2004, late 2004, and 2005 models:[/FONT]

• [FONT='Arial','sans-serif']Park Distance Control was standard in 2005's but was an option in 2004[/FONT]
• [FONT='Arial','sans-serif']Blue Tooth and The BMW Assist Feature can exist and function together in 2005's (not in the 04's)[/FONT]
• [FONT='Arial','sans-serif']Xenon Headlights are Adaptive (they turn to the right when the steering wheel turns right) in 2005's (not in 04's)[/FONT]
• [FONT='Arial','sans-serif']Early 2004’s didn’t have the panoramic sunroof option[/FONT]
• [FONT='Arial','sans-serif']Early 2004’s didn’t have blue tooth[/FONT]
• [FONT='Arial','sans-serif'][FONT='Arial','sans-serif']The tire pressure monitor option was available in late 2004’s and 2005’s but not available in early 2004’s[/FONT][/FONT]

Happy hunting!